Click below to expand and view problems.

Arrays

• https://leetcode.com/problems/3sum/ Medium
• https://leetcode.com/problems/add-to-array-form-of-integer/ Easy
• https://leetcode.com/problems/all-divisions-with-the-highest-score-of-a-binary-array/ Medium
• https://leetcode.com/problems/build-array-from-permutation/ Easy
• https://leetcode.com/problems/cells-with-odd-values-in-a-matrix/ Easy
• https://leetcode.com/problems/check-if-every-row-and-column-contains-all-numbers/ Easy
• https://leetcode.com/problems/check-if-the-sentence-is-pangram/ Easy
• https://leetcode.com/problems/combination-sum/ Medium
• https://leetcode.com/problems/concatenation-of-array/ Easy
• https://leetcode.com/problems/contiguous-array/ Medium
• https://leetcode.com/problems/count-elements-with-strictly-smaller-and-greater-elements/ Easy
• https://leetcode.com/problems/count-items-matching-a-rule/ Easy
• https://leetcode.com/problems/create-target-array-in-the-given-order/ Easy
• https://leetcode.com/problems/determine-whether-matrix-can-be-obtained-by-rotation/ Easy
• https://leetcode.com/problems/find-all-lonely-numbers-in-the-array/ Medium
• https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/ Medium
• https://leetcode.com/problems/find-first-palindromic-string-in-the-array/ Easy
• https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero/ Easy
• https://leetcode.com/problems/find-numbers-with-even-number-of-digits/ Easy
• https://leetcode.com/problems/find-the-highest-altitude/ Easy
• https://leetcode.com/problems/flipping-an-image/ Easy
• https://leetcode.com/problems/house-robber/ Medium
• https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number/ Easy
• https://leetcode.com/problems/intersection-of-two-arrays-ii/ Easy
• https://leetcode.com/problems/jump-game/ Medium
• https://leetcode.com/problems/keep-multiplying-found-values-by-two/ Easy
• https://leetcode.com/problems/kids-with-the-greatest-number-of-candies/ Easy
• https://leetcode.com/problems/kids-with-the-greatest-number-of-candies/ Easy
• https://leetcode.com/problems/lucky-numbers-in-a-matrix/ Easy
• https://leetcode.com/problems/majority-element/ Easy
• https://leetcode.com/problems/matrix-diagonal-sum/ Easy
• https://leetcode.com/problems/matrix-diagonal-sum/ Easy
• https://leetcode.com/problems/maximize-distance-to-closest-person/ Medium
• https://leetcode.com/problems/maximum-population-year/ Easy
• https://leetcode.com/problems/maximum-subarray/ Easy
• https://leetcode.com/problems/median-of-two-sorted-arrays/ Hard
• https://leetcode.com/problems/merge-sorted-array/ Easy
• https://leetcode.com/problems/minimum-swaps-to-group-all-1s-together-ii/ Medium
• https://leetcode.com/problems/number-of-good-pairs/ Easy
• https://leetcode.com/problems/number-of-smooth-descent-periods-of-a-stock/ Medium
• https://leetcode.com/problems/partition-array-according-to-given-pivot/ Medium
• https://leetcode.com/problems/pascals-triangle/ Easy
• https://leetcode.com/problems/permutations-ii/ Medium Recursion
• https://leetcode.com/problems/plus-one/ Easy
• https://leetcode.com/problems/product-of-array-except-self/ Medium
• https://leetcode.com/problems/rearrange-array-elements-by-sign/ Medium
• https://leetcode.com/problems/remove-duplicates-from-sorted-array/ Easy
• https://leetcode.com/problems/reshape-the-matrix/ Easy
• https://leetcode.com/problems/richest-customer-wealth/ Easy
• https://leetcode.com/problems/rotate-array/ Medium
• https://leetcode.com/problems/running-sum-of-1d-array/ Easy
• https://leetcode.com/problems/set-matrix-zeroes/ Medium
• https://leetcode.com/problems/shuffle-the-array/ Easy
• https://leetcode.com/problems/sort-colors/ Medium
• https://leetcode.com/problems/spiral-matrix-ii/ Medium
• https://leetcode.com/problems/largest-positive-integer-that-exists-with-its-negative/ Medium
• https://leetcode.com/problems/valid-mountain-array/ Easy
• https://leetcode.com/problems/find-all-k-distant-indices-in-an-array/ Easy Recommended
• https://leetcode.com/problems/get-the-maximum-score/ Hard
• https://leetcode.com/problems/count-number-of-pairs-with-absolute-difference-k/ Easy
• https://leetcode.com/problems/next-permutation/ Medium
• https://leetcode.com/problems/3sum-with-multiplicity/ Medium
• https://leetcode.com/problems/baseball-game/ Easy
• https://leetcode.com/problems/shift-2d-grid/ Easy
• https://leetcode.com/problems/game-of-life/ Medium
• https://leetcode.com/problems/move-zeroes/ Easy
• https://leetcode.com/problems/find-the-k-beauty-of-a-number/ Easy
• https://leetcode.com/problems/squares-of-a-sorted-array/ Easy
• https://leetcode.com/problems/pascals-triangle-ii/ Easy
• https://leetcode.com/problems/partition-array-such-that-maximum-difference-is-k/ Medium
• https://leetcode.com/problems/calculate-amount-paid-in-taxes/ Easy
• https://leetcode.com/problems/check-if-matrix-is-x-matrix/ Easy
• https://leetcode.com/problems/convert-1d-array-into-2d-array/ Easy
• https://leetcode.com/problems/rotate-image/ Medium
• https://leetcode.com/problems/island-perimeter/ Easy
• https://leetcode.com/problems/diagonal-traverse/ Medium
• https://leetcode.com/problems/diagonal-traverse/ Medium
• https://leetcode.com/problems/alphabet-board-path/ Medium
• https://leetcode.com/problems/the-employee-that-worked-on-the-longest-task/ Easy
• https://leetcode.com/problems/largest-positive-integer-that-exists-with-its-negative/ Easy
• https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent/ Easy
• https://leetcode.com/problems/print-words-vertically/ Medium
• https://leetcode.com/problems/max-consecutive-ones/ Easy
• https://leetcode.com/problems/shortest-distance-to-target-string-in-a-circular-array/ Easy
• https://leetcode.com/problems/delete-columns-to-make-sorted/description/ Easy
• https://leetcode.com/problems/decompress-run-length-encoded-list/ Easy
• https://leetcode.com/problems/shuffle-an-array/ Medium
• https://leetcode.com/problems/row-with-maximum-ones/ Easy
• https://leetcode.com/problems/watering-plants/ Medium
• https://leetcode.com/problems/subrectangle-queries/ Medium

Bit Manipulation

• https://leetcode.com/problems/binary-number-with-alternating-bits/ Easy
• https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero/ Easy
• https://leetcode.com/problems/single-number/ Easy
• https://leetcode.com/problems/check-if-a-string-contains-all-binary-codes-of-size-k/ Medium
• https://leetcode.com/problems/maximum-product-of-word-lengths/ Medium
• https://leetcode.com/problems/divide-two-integers/ Medium
• https://leetcode.com/problems/longest-nice-subarray/ Medium
• https://leetcode.com/problems/longest-subarray-with-maximum-bitwise-and/ Medium
• https://leetcode.com/problems/decode-xored-array/description/ ```Easy``
• https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero/ Easy
• https://leetcode.com/problems/xor-operation-in-an-array/description/ Easy
• https://leetcode.com/problems/find-the-original-array-of-prefix-xor/ Medium
• https://leetcode.com/problems/binary-number-with-alternating-bits/ Medium
• https://leetcode.com/problems/gray-code/ Medium
• https://leetcode.com/problems/single-number-ii/description/ Medium
• https://leetcode.com/problems/find-xor-sum-of-all-pairs-bitwise-and/ ``Hard```
• https://leetcode.com/problems/hamming-distance/ Easy
• https://leetcode.com/problems/bitwise-and-of-numbers-range Medium
• https://leetcode.com/problems/maximum-strong-pair-xor-i/ Medium
• https://leetcode.com/problems/find-unique-binary-string/ Medium

Backtracking

• https://leetcode.com/problems/generate-parentheses/ Medium
• https://leetcode.com/problems/combination-sum/ Medium
• https://leetcode.com/problems/combination-sum-ii/ Medium
• https://leetcode.com/problems/n-queens/ Hard
• https://leetcode.com/problems/n-queens-ii/ Hard
• https://leetcode.com/problems/combinations/ Medium
• https://leetcode.com/problems/matchsticks-to-square```Medium```
• https://leetcode.com/problems/maximum-rows-covered-by-columns/ Medium
• https://leetcode.com/problems/sudoku-solver/ Hard
• https://leetcode.com/problems/subsets-ii/ Medium
• https://leetcode.com/problems/find-xor-beauty-of-array/ Medium
• https://leetcode.com/problems/restore-ip-addresses/ Medium
• https://leetcode.com/problems/the-number-of-beautiful-subsets/ Medium
• https://leetcode.com/problems/additive-number/ Medium
• https://leetcode.com/problems/letter-tile-possibilities/ Medium
• https://leetcode.com/problems/number-of-ways-to-reorder-array-to-get-same-bst/ Hard

Design

• https://leetcode.com/problems/design-an-atm-machine/ Medium
• https://leetcode.com/problems/min-stack/ Easy
• https://leetcode.com/problems/design-hashset/ Easy
• https://leetcode.com/problems/design-hashmap/ Easy
• https://leetcode.com/problems/encode-and-decode-tinyurl/ Medium
• https://leetcode.com/problems/peeking-iterator/ Medium
• https://leetcode.com/problems/implement-stack-using-queues/ Easy
• https://leetcode.com/problems/fair-distribution-of-cookies/submissions/ Medium
• https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant/ Medium
• https://leetcode.com/problems/design-browser-history/ Medium
• https://leetcode.com/problems/design-front-middle-back-queue/ Medium
• https://leetcode.com/problems/find-consecutive-integers-from-a-data-stream/ Medium
• https://leetcode.com/problems/random-pick-index/ Medium
• https://leetcode.com/problems/frequency-tracker/ Medium
• https://leetcode.com/problems/design-parking-system/ Medium

Dynamic Programming

• https://leetcode.com/problems/coin-change/ Medium
• https://leetcode.com/problems/coin-change-2/ Medium
• https://leetcode.com/problems/arithmetic-slices/ Medium
• https://leetcode.com/problems/champagne-tower/ Medium
• https://leetcode.com/problems/best-time-to-buy-and-sell-stock/ Easy
• https://leetcode.com/problems/climbing-stairs/ Easy
• https://leetcode.com/problems/n-th-tribonacci-number/ Easy
• https://leetcode.com/problems/divisor-game/ Easy
• https://leetcode.com/problems/min-cost-climbing-stairs/ Easy
• https://leetcode.com/problems/longest-increasing-subsequence/ Medium
• https://practice.geeksforgeeks.org/problems/max-sum-without-adjacents2430/1 Easy
• https://leetcode.com/problems/delete-and-earn/ Medium
• https://leetcode.com/problems/number-of-smooth-descent-periods-of-a-stock/ Medium
• https://leetcode.com/problems/counting-bits/ Easy Bit Manipulation
• https://leetcode.com/problems/integer-break/ Medium
• https://leetcode.com/problems/minimum-cost-for-tickets/ Medium
• https://leetcode.com/problems/decode-ways/ Medium
• https://practice.geeksforgeeks.org/problems/subset-sum-problem-1611555638/1/ Medium Recommended
• https://leetcode.com/problems/partition-equal-subset-sum/ Medium
• https://practice.geeksforgeeks.org/problems/perfect-sum-problem5633/1# Medium Standard
• https://leetcode.com/problems/target-sum/ Medium Recommended
• https://www.codingninjas.com/codestudio/problems/rod-cutting-problem_800284 Medium
• https://leetcode.com/problems/longest-common-subsequence/ Medium Standard
• https://leetcode.com/problems/letter-combinations-of-a-phone-number/ Medium
• https://leetcode.com/problems/delete-operation-for-two-strings/ Medium
• https://leetcode.com/problems/minimum-ascii-delete-sum-for-two-strings/ Medium
• https://leetcode.com/problems/n-th-tribonacci-number/te-sum-for-two-strings/ Medium
• https://leetcode.com/problems/longest-palindromic-subsequence/ Medium
• https://leetcode.com/problems/jump-game-ii/ Medium
• https://leetcode.com/problems//minimum-insertion-steps-to-make-a-string-palindrome/ Hard
• https://leetcode.com/problems/shortest-common-supersequence/ Hard
• https://leetcode.com/problems/palindrome-partitioning/ Medium
• https://leetcode.com/problems/palindrome-partitioning-ii/ Hard
• https://leetcode.com/problems/perfect-squares/ Medium
• https://leetcode.com/problems/number-of-ways-to-buy-pens-and-pencils/ Medium
• https://leetcode.com/problems/count-sorted-vowel-strings/ Medium
• https://leetcode.com/problems/get-maximum-in-generated-array/ Easy
• https://leetcode.com/problems/unique-paths-ii/ Medium
• https://leetcode.com/problems/palindromic-substrings/ Medium
• https://leetcode.com/problems/concatenated-words/ Hard
• https://leetcode.com/problems/word-break/ Medium
• https://leetcode.com/problems/word-break-ii/ Hard
• https://leetcode.com/problems/unique-paths/ Medium
• https://leetcode.com/problems/triangle/ Medium
• https://leetcode.com/problems/minimum-path-cost-in-a-grid/ Medium
• https://leetcode.com/problems/edit-distance/ Hard
• https://leetcode.com/problems/longest-string-chain/ Medium
• https://leetcode.com/problems/maximum-profit-in-job-scheduling/ Hard
• https://leetcode.com/problems/maximum-earnings-from-taxi/ Medium
• https://leetcode.com/problems/jump-game/ Medium
• https://leetcode.com/problems/string-compression/ Medium
• https://leetcode.com/problems/time-needed-to-rearrange-a-binary-string/ Medium
• https://leetcode.com/problems/minimum-path-sum/ Medium
• https://leetcode.com/problems/fibonacci-number/ Easy
• https://leetcode.com/problems/length-of-longest-fibonacci-subsequence/ Medium
• https://leetcode.com/problems/interleaving-string/ Medium
• https://leetcode.com/problems/out-of-boundary-paths/ Medium
• https://leetcode.com/problems/knight-probability-in-chessboard/ Medium
• https://leetcode.com/problems/check-if-there-is-a-valid-partition-for-the-array/ Medium
• https://leetcode.com/problems/k-concatenation-maximum-sum/ Medium
• https://leetcode.com/problems/number-of-ways-to-reach-a-position-after-exactly-k-steps/ Medium
• https://leetcode.com/problems/count-square-submatrices-with-all-ones/ Medium
• https://leetcode.com/problems/all-possible-full-binary-trees/ Medium
• https://leetcode.com/problems/minimum-number-of-removals-to-make-mountain-array/ Hard
• https://leetcode.com/problems/max-dot-product-of-two-subsequences/ Medium
• https://leetcode.com/problems/number-of-dice-rolls-with-target-sum/ Medium
• https://leetcode.com/problems/where-will-the-ball-fall/ Medium
• https://leetcode.com/problems/unique-binary-search-trees/ Medium
• https://leetcode.com/problems/find-the-substring-with-maximum-cost/ Medium
• https://leetcode.com/problems/maximum-product-subarray/ Medium
• https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/ Medium
• https://leetcode.com/problems/different-ways-to-add-parentheses/ Medium
• https://leetcode.com/problems/unique-binary-search-trees-ii/ Medium
• https://leetcode.com/problems/profitable-schemes/ Hard
• https://leetcode.com/problems/maximum-value-of-k-coins-from-piles/ Hard
• https://leetcode.com/problems/uncrossed-lines/ Medium
• https://leetcode.com/problems/make-array-strictly-increasing/ Hard
• https://leetcode.com/problems/number-of-increasing-paths-in-a-grid/ Hard
• https://leetcode.com/problems/number-of-music-playlists/ hard

Graphs

• https://leetcode.com/problems/flood-fill/ Easy
• https://leetcode.com/problems/is-graph-bipartite/ Medium
• https://leetcode.com/problems/jump-game-vii/ Medium
• https://leetcode.com/problems/find-center-of-star-graph/ Easy
• https://leetcode.com/problems/reachable-nodes-with-restrictions/ Medium
• https://leetcode.com/problems/snakes-and-ladders/ Medium
• https://leetcode.com/problems/max-area-of-island/ Medium
• https://leetcode.com/problems/minimum-jumps-to-reach-home/ Medium
• https://leetcode.com/problems/lexicographical-numbers/ Medium
• https://leetcode.com/problems/word-search/ Medium
• https://leetcode.com/problems/find-if-path-exists-in-graph/ Easy
• https://leetcode.com/problems/find-the-town-judge/ Easy
• https://leetcode.com/problems/minimum-number-of-vertices-to-reach-all-nodes/ Medium
• https://leetcode.com/problems/all-paths-from-source-to-target/ Medium
• https://leetcode.com/problems/keys-and-rooms/ Medium
• https://leetcode.com/problems/pacific-atlantic-water-flow/ Medium
• https://leetcode.com/problems/numbers-with-same-consecutive-differences/ Medium
• https://leetcode.com/problems/minimum-genetic-mutation/ Medium
• https://leetcode.com/problems/nearest-exit-from-entrance-in-maze/ Medium
• https://leetcode.com/problems/minimum-score-of-a-path-between-two-cities/ Medium
• https://leetcode.com/problems/unique-paths-iii/ Hard
• https://leetcode.com/problems/shortest-path-with-alternating-colors/ Medium
• https://leetcode.com/problems/minimum-fuel-cost-to-report-to-the-capital/ Medium
• https://leetcode.com/problems/minimum-distance-between-bst-nodes/ Easy
• https://leetcode.com/problems/check-knight-tour-configuration/ Medium
• https://leetcode.com/problems/number-of-closed-islands/ Medium
• https://leetcode.com/problems/surrounded-regions/ Medium
• https://leetcode.com/problems/number-of-enclaves/ Medium
• https://leetcode.com/problems/course-schedule/ Medium
• https://leetcode.com/problems/course-schedule-ii/ Medium
• https://leetcode.com/problems/rotting-oranges/ Medium
• https://leetcode.com/problems/evaluate-division/ Medium
• https://leetcode.com/problems/shortest-bridge/ Medium
• https://leetcode.com/problems/time-needed-to-inform-all-employees/ Medium
• https://leetcode.com/problems/number-of-provinces/ Medium
• https://leetcode.com/problems/minimum-number-of-pushes-to-type-word-i/ Medium

Greedy

• https://leetcode.com/problems/can-place-flowers/ Easy
• https://leetcode.com/problems/container-with-most-water/ Medium
• https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons/ Medium
• https://leetcode.com/problems/non-overlapping-intervals/ Medium
• https://leetcode.com/problems/merge-intervals/ Medium
• https://leetcode.com/problems/remove-covered-intervals/ Medium
• https://leetcode.com/problems/teemo-attacking/ Easy
• https://leetcode.com/problems/gas-station/ Easy
• https://leetcode.com/problems/last-stone-weight/ Easy
• https://leetcode.com/problems/partition-labels/ Medium
• https://leetcode.com/problems/smallest-string-with-a-given-numeric-value/ Medium
• https://leetcode.com/problems/broken-calculator/ Medium
• https://leetcode.com/problems/boats-to-save-people/ Medium
• https://leetcode.com/problems/two-city-scheduling/ Medium
• https://leetcode.com/problems/container-with-most-water/ Medium
• https://leetcode.com/problems/minimum-number-of-operations-to-convert-time/ Easy
• https://leetcode.com/problems/minimum-rounds-to-complete-all-tasks/ Medium
• https://leetcode.com/problems/removing-minimum-and-maximum-from-array/ Medium
• https://leetcode.com/problems/partitioning-into-minimum-number-of-deci-binary-numbers/ Medium
• https://leetcode.com/problems/largest-number/ Medium
• https://leetcode.com/problems/smallest-value-of-the-rearranged-number/ Medium
• https://leetcode.com/problems/minimum-moves-to-equal-array-elements/ Medium
• https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii/ Medium
• https://leetcode.com/problems/minimum-operations-to-make-a-uni-value-grid/ Medium
• https://leetcode.com/problems/maximum-units-on-a-truck/ Easy
• https://leetcode.com/problems/maximum-area-of-a-piece-of-cake-after-horizontal-and-vertical-cuts/ Medium
• https://leetcode.com/problems/wiggle-subsequence/ Medium
• https://leetcode.com/problems/candy/ Hard
• https://leetcode.com/problems/longest-consecutive-sequence/ Medium
• https://leetcode.com/problems/maximum-consecutive-floors-without-special-floors/ Medium
• https://leetcode.com/problems/max-area-of-island/ Medium
• https://leetcode.com/problems/split-array-into-consecutive-subsequences/ Medium
• https://leetcode.com/problems/two-furthest-houses-with-different-colors/ Easy
• https://leetcode.com/problems/bag-of-tokens/ Medium
• https://leetcode.com/problems/find-original-array-from-doubled-array/ Medium
• https://leetcode.com/problems/minimum-time-to-make-rope-colorful/description/ Medium
• https://leetcode.com/problems/break-a-palindrome/ Medium
• https://leetcode.com/problems/minimize-maximum-pair-sum-in-array/ Medium
• https://leetcode.com/problems/remove-digit-from-number-to-maximize-result/ Easy
• https://leetcode.com/problems/max-increase-to-keep-city-skyline/ Medium
• https://leetcode.com/problems/maximum-number-of-coins-you-can-get/ Medium
• https://leetcode.com/problems/score-after-flipping-matrix/ Medium
• https://leetcode.com/problems/find-valid-matrix-given-row-and-column-sums/ Medium
• https://leetcode.com/problems/take-k-of-each-character-from-left-and-right/ Medium
• https://leetcode.com/problems/partition-string-into-substrings-with-values-at-most-k/ Medium
• https://leetcode.com/problems/maximum-ice-cream-bars/ Medium
• https://leetcode.com/problems/make-number-of-distinct-characters-equal/ Medium
• https://leetcode.com/problems/insert-interval/ Medium
• https://leetcode.com/problems/maximum-difference-by-remapping-a-digit/ Easy
• https://leetcode.com/problems/minimum-score-by-changing-two-elements/ Medium
• https://leetcode.com/problems/minimum-operations-to-reduce-an-integer-to-0/ Easy
• https://leetcode.com/problems/merge-two-2d-arrays-by-summing-values/ Easy
• https://leetcode.com/problems/find-the-maximum-number-of-marked-indices Medium
• https://leetcode.com/problems/count-ways-to-group-overlapping-ranges/ Medium
• https://leetcode.com/problems/distribute-money-to-maximum-children/ Medium
• https://leetcode.com/problems/smallest-missing-non-negative-integer-after-operations/ Medium
• https://leetcode.com/problems/prime-subtraction-operation/ Medium
• https://leetcode.com/problems/k-items-with-the-maximum-sum/ Easy
• https://leetcode.com/problems/mice-and-cheese/ Medium
• https://leetcode.com/problems/lexicographically-smallest-string-after-substring-operation/ Medium
• https://leetcode.com/problems/maximum-element-after-decreasing-and-rearranging/ Medium
• https://leetcode.com/problems/reduction-operations-to-make-the-array-elements-equal/editorial/ Medium
• https://leetcode.com/problems/minimum-number-of-pushes-to-type-word-ii/ Medium

HashTable

• https://leetcode.com/problems/number-of-matching-subsequences/ Medium
• https://leetcode.com/problems/contains-duplicate-ii/ Easy
• https://leetcode.com/problems/find-players-with-zero-or-one-losses/ Medium
• https://leetcode.com/problems/kth-distinct-string-in-an-array/ Easy
• https://leetcode.com/problems/max-number-of-k-sum-pairs/ Medium
• https://leetcode.com/problems/contains-duplicate/ Easy
• https://leetcode.com/problems/contains-duplicate-iii/ Medium
• https://leetcode.com/problems/replace-elements-in-an-array/ Medium
• https://leetcode.com/problems/longest-harmonious-subsequence/ Medium
• https://leetcode.com/problems/distribute-candies/ Easy
• https://leetcode.com/problems/prefix-and-suffix-search/ Hard
• https://leetcode.com/problems/longest-word-in-dictionary/ Medium
• https://leetcode.com/problems/minimum-deletions-to-make-character-frequencies-unique/ Medium
• https://leetcode.com/problems/decode-the-message/ Easy
• https://leetcode.com/problems/maximum-number-of-pairs-in-array/ Easy
• https://leetcode.com/problems/max-sum-of-a-pair-with-equal-sum-of-digits/ Medium
• https://leetcode.com/problems/query-kth-smallest Medium
• https://leetcode.com/problems/minimum-area-rectangle/ Medium
• https://leetcode.com/problems/find-and-replace-pattern/ Medium
• https://leetcode.com/problems/number-of-arithmetic-triplets/ Easy
• https://leetcode.com/problems/merge-similar-items/ Easy
• https://leetcode.com/problems/count-number-of-bad-pairs/ Medium
• https://leetcode.com/problems/largest-palindromic-number/ Medium
• https://leetcode.com/problems/ransom-note/ Easy
• https://leetcode.com/problems/count-common-words-with-one-occurrence/ Easy
• https://leetcode.com/problems/find-subarrays-with-equal-sum/ Medium
• https://leetcode.com/problems/check-distances-between-same-letters/ Easy
• https://leetcode.com/problems/find-duplicate-file-in-system/ Medium
• https://leetcode.com/problems/count-number-of-distinct-integers-after-reverse-operations/ Medium
• https://leetcode.com/problems/majority-element-ii/ Medium
• https://leetcode.com/problems/maximum-sum-of-distinct-subarrays-with-length-k/ Medium
• https://leetcode.com/problems/most-popular-video-creator/ Medium
• https://leetcode.com/problems/task-scheduler/ Medium
• https://leetcode.com/problems/valid-sudoku/ Medium
• https://leetcode.com/problems/determine-if-two-strings-are-close/ Medium
• https://leetcode.com/problems/divide-players-into-teams-of-equal-skill/ Medium
• https://leetcode.com/problems/form-smallest-number-from-two-digit-arrays/ Easy
• https://leetcode.com/problems/subdomain-visit-count/ Medium
• https://leetcode.com/problems/bulls-and-cows/ Medium
• https://leetcode.com/problems/rle-iterator/ Medium
• https://leetcode.com/problems/count-servers-that-communicate/ Medium
• https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagram/ Medium
• https://leetcode.com/problems/find-the-distinct-difference-array/ Easy
• https://leetcode.com/problems/finding-the-users-active-minutes/ Medium
• https://leetcode.com/problems/group-the-people-given-the-group-size-they-belong-to/ Medium

Heap

• https://leetcode.com/problems/last-stone-weight/ Easy Recommended
• https://leetcode.com/problems/top-k-frequent-elements/ Medium
• https://leetcode.com/problems/furthest-building-you-can-reach/ Medium
• https://leetcode.com/problems/course-schedule-iii/ Hard
• https://leetcode.com/problems/construct-target-array-with-multiple-sums/ Hard
• https://leetcode.com/problems/sort-the-matrix-diagonally/ Medium
• https://leetcode.com/problems/sliding-window-maximum/ Hard
• https://leetcode.com/problems/minimum-deletions-to-make-array-divisible/ Hard
• https://leetcode.com/problems/minimum-amount-of-time-to-fill-cups/ Easy
• https://leetcode.com/problems/reduce-array-size-to-the-half/ Medium
• https://leetcode.com/problems/divide-intervals-into-minimum-number-of-groups/ Medium
• https://leetcode.com/problems/sort-the-people/ Easy
• https://leetcode.com/problems/total-cost-to-hire-k-workers/ Medium
• https://leetcode.com/problems/remove-stones-to-minimize-the-total/ Medium
• https://leetcode.com/problems/convert-an-array-into-a-2d-array-with-conditions/ Medium
• https://leetcode.com/problems/distant-barcodes/ Medium
• https://leetcode.com/problems/largest-values-from-labels/ Medium

LinkedLists

• https://leetcode.com/problems/maximum-twin-sum-of-a-linked-list/ Medium
• https://leetcode.com/problems/merge-k-sorted-lists/ Hard
• https://leetcode.com/problems/merge-nodes-in-between-zeros/ Medium
• https://leetcode.com/problems/remove-duplicates-from-sorted-list/ Medium
• https://leetcode.com/problems/swap-nodes-in-pairs/ Medium
• https://leetcode.com/problems/merge-two-sorted-lists/ Easy
• https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/ Medium
• https://leetcode.com/problems/linked-list-cycle/ Easy
• https://leetcode.com/problems/add-two-numbers/ Medium
• https://leetcode.com/problems/rotate-list/ Medium
• https://leetcode.com/problems/copy-list-with-random-pointer/ Medium
• https://leetcode.com/problems/remove-nth-node-from-end-of-list/ Medium
• https://leetcode.com/problems/swapping-nodes-in-a-linked-list/ Medium
• https://leetcode.com/problems/plus-one-linked-list/ Medium Premium
• https://leetcode.com/problems/intersection-of-two-linked-lists/ Easy
• https://leetcode.com/problems/partition-list/ Medium
• https://leetcode.com/problems/reverse-linked-list-ii/ Medium
• https://leetcode.com/problems/reverse-linked-list/ Easy
• https://leetcode.com/problems/palindrome-linked-list/ Easy
• https://leetcode.com/problems/merge-in-between-linked-lists/ Medium
• https://leetcode.com/problems/middle-of-the-linked-list/ Easy
• https://leetcode.com/problems/linked-list-cycle-ii/ Medium
• https://leetcode.com/problems/delete-node-in-a-linked-list/ Medium
• https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list Medium
• https://leetcode.com/problems/reorder-list/ Medium
• https://leetcode.com/problems/remove-nodes-from-linked-list/ Medium
• https://leetcode.com/problems/odd-even-linked-list/ Medium
• https://leetcode.com/problems/remove-linked-list-elements/ Easy
• https://leetcode.com/problems/reverse-nodes-in-k-group/ Hard
• https://leetcode.com/problems/add-two-numbers-ii/ Medium

Maths

• https://leetcode.com/problems/add-digits/ Easy
• https://leetcode.com/problems/happy-number/ Easy
• https://leetcode.com/problems/find-numbers-with-even-number-of-digits/ Easy
• https://leetcode.com/problems/smallest-integer-divisible-by-k/ Medium
• https://leetcode.com/problems/minimum-moves-to-reach-target-score/ Medium Greedy
• https://leetcode.com/problems/minimum-sum-of-four-digit-number-after-splitting-digits/ Easy
• https://leetcode.com/problems/find-three-consecutive-integers-that-sum-to-a-given-number/ Medium
• https://leetcode.com/problems/count-integers-with-even-digit-sum/ Easy
• https://leetcode.com/problems/number-of-1-bits/ Easy
• https://leetcode.com/problems/largest-number-after-digit-swaps-by-parity/ Easy
• https://leetcode.com/problems/minimize-result-by-adding-parentheses-to-expression/ Medium
• https://leetcode.com/problems/maximum-product-after-k-increments/k Medium
• https://leetcode.com/problems/design-an-atm-machine/ Medium
• https://leetcode.com/problems/count-lattice-points-inside-a-circle/ Medium
• https://leetcode.com/problems/super-pow/ Medium
• https://leetcode.com/problems/count-nice-pairs-in-an-array/ Medium
• https://leetcode.com/problems/count-number-of-rectangles-containing-each-point/ Medium
• https://leetcode.com/problems/power-of-three/ Easy
• https://leetcode.com/problems/power-of-four/ Easy
• https://leetcode.com/problems/power-of-two Easy
• https://leetcode.com/problems/reordered-power-of-2/ ````Medium```
• https://leetcode.com/problems/reverse-bits/ Easy
• https://leetcode.com/problems/subtract-the-product-and-sum-of-digits-of-an-integer/ Easy
• https://leetcode.com/problems/strictly-palindromic-number/ Medium
• https://leetcode.com/problems/largest-perimeter-triangle/ Easy
• https://leetcode.com/problems/sum-of-number-and-its-reverse/ Medium
• https://leetcode.com/problems/average-value-of-even-numbers-that-are-divisible-by-three/ Easy
• https://leetcode.com/problems/minimum-addition-to-make-integer-beautiful/ Medium
• https://leetcode.com/problems/smallest-value-after-replacing-with-sum-of-prime-factors/ Medium
• https://leetcode.com/problems/categorize-box-according-to-criteria/ Easy
• https://leetcode.com/problems/count-distinct-numbers-on-board/ Easy
• https://leetcode.com/problems/minimum-impossible-or Easy
• https://leetcode.com/problems/find-the-divisibility-array-of-a-string/ Medium
• https://leetcode.com/problems/partition-array-into-three-parts-with-equal-sum/ Easy
• https://leetcode.com/problems/pass-the-pillow/ Easy
• https://leetcode.com/problems/make-k-subarray-sums-equal/ Medium
• https://leetcode.com/problems/sum-of-absolute-differences-in-a-sorted-array/ Medium
• https://leetcode.com/problems/nim-game/ Maths
• https://leetcode.com/problems/factorial-trailing-zeroes/ Medium
• https://leetcode.com/problems/fraction-to-recurring-decimal/ Medium
• https://leetcode.com/problems/prime-in-diagonal/ Easy
• https://leetcode.com/problems/fizz-buzz/ Easy
• https://leetcode.com/problems/third-maximum-number/ Easy
• https://leetcode.com/problems/add-strings/ Easy
• https://leetcode.com/problems/number-complement/ Easy
• https://leetcode.com/problems/find-the-maximum-divisibility-score/ Easy
• https://leetcode.com/problems/rotate-function/ Medium
• https://leetcode.com/problems/find-the-punishment-number-of-an-integer/ Medium

Prefix Sum

• https://leetcode.com/problems/minimum-size-subarray-sum/ Medium
• https://leetcode.com/problems/product-of-array-except-self/ Medium
• https://leetcode.com/problems/range-sum-query-immutable/ Easy
• https://leetcode.com/problems/range-sum-query-2d-immutable/ Medium
• https://leetcode.com/problems/continuous-subarray-sum/ Medium
• https://leetcode.com/problems/find-pivot-index/ Easy
• https://leetcode.com/problems/sum-of-all-odd-length-subarrays/ Easy
• https://leetcode.com/problems/minimum-value-to-get-positive-step-by-step-sum/ Easy
• https://leetcode.com/problems/find-the-middle-index-in-array/submissions/ Easy
• https://leetcode.com/problems/running-sum-of-1d-array/ Easy
• https://leetcode.com/problems/minimum-average-difference/ Medium
• https://leetcode.com/problems/top-k-frequent-words/ Easy
• https://leetcode.com/problems/number-of-ways-to-split-array/ Medium
• https://leetcode.com/problems/random-pick-with-weight/ Medium
• https://leetcode.com/problems/minimum-operations-to-reduce-x-to-zero/ Medium
• https://leetcode.com/problems/count-subarrays-with-score-less-than-k/ Medium
• https://leetcode.com/problems/maximum-erasure-value/ Medium
• https://leetcode.com/problems/non-decreasing-array/ Medium
• https://leetcode.com/problems/frequency-of-the-most-frequent-element/ Medium
• https://leetcode.com/problems/xor-queries-of-a-subarray/ Medium
• https://leetcode.com/problems/maximum-points-you-can-obtain-from-cards/ Medium
• https://leetcode.com/problems/find-good-days-to-rob-the-bank/ Medium
• https://leetcode.com/problems/shifting-letters/ Medium
• https://leetcode.com/problems/shifting-letters-ii/ Medium
• https://leetcode.com/problems/longest-subsequence-with-limited-sum/ Easy
• https://leetcode.com/problems/minimum-amount-of-time-to-collect-garbage/ Medium
• https://leetcode.com/problems/find-all-good-indices/ Medium
• https://leetcode.com/problems/find-the-pivot-integer/ Easy
• https://leetcode.com/problems/left-and-right-sum-differences/ Easy
• https://leetcode.com/problems/minimum-operations-to-make-all-array-elements-equal/ Medium
• https://leetcode.com/problems/corporate-flight-bookings/ Medium
• https://leetcode.com/problems/sum-of-distances/ Medium
• https://leetcode.com/problems/find-the-score-of-all-prefixes-of-an-array/ Medium
• https://leetcode.com/problems/binary-subarrays-with-sum/ Medium
• https://leetcode.com/problems/minimum-number-of-operations-to-move-all-balls-to-each-box/ Medium
• https://leetcode.com/problems/k-radius-subarray-averages/ Medium

Queue

• https://leetcode.com/problems/implement-queue-using-stacks/ Easy
• https://leetcode.com/problems/time-needed-to-buy-tickets/ Easy
• https://www.codingninjas.com/reverse-first-k-elements-of-queue Easy
• https://leetcode.com/problems/design-circular-queue/ Medium
• https://leetcode.com/problems/find-the-winner-of-the-circular-game/ Medium
• https://leetcode.com/problems/design-front-middle-back-queue/ Medium
• https://leetcode.com/problems/product-of-the-last-k-numbers/ Medium
• https://leetcode.com/problems/shortest-path-in-binary-matrix/ Medium

Recursion

• https://www.geeksforgeeks.org/sum-triangle-from-array/ Easy GFG
• https://leetcode.com/problems/sudoku-solver/ Hard
• https://leetcode.com/problems/combination-sum-iii/ Medium
• https://leetcode.com/problems/elimination-game/ Medium
• https://leetcode.com/problems/k-th-symbol-in-grammar/ Medium
• https://leetcode.com/problems/count-and-say/ Medium
• https://leetcode.com/problems/find-kth-bit-in-nth-binary-string/ Medium
• https://leetcode.com/problems/construct-quad-tree/ Medium

Search

• https://leetcode.com/problems/arranging-coins/ Easy
• https://leetcode.com/problems/binary-search/ Very Easy
• https://leetcode.com/problems/check-if-n-and-its-double-exist/ Easy
• https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix/ Medium
• https://leetcode.com/problems/count-negative-numbers-in-a-sorted-matrix/ Easy
• https://leetcode.com/problems/fair-candy-swap/ Easy
• https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/ Easy
• https://leetcode.com/problems/find-in-mountain-array/ Hard
• https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/ Medium
• https://leetcode.com/problems/find-smallest-letter-greater-than-target/ Easy
• https://leetcode.com/problems/first-bad-version/ Very Easy
• https://leetcode.com/problems/guess-number-higher-or-lower/ Very Easy
• https://leetcode.com/problems/intersection-of-two-arrays-ii/ Easy
• https://leetcode.com/problems/intersection-of-two-arrays/ Easy
• https://leetcode.com/problems/single-element-in-a-sorted-array/ Medium
• https://leetcode.com/problems/special-array-with-x-elements-greater-than-or-equal-x/ Easy
• https://leetcode.com/problems/sqrtx/ Very Easy
• https://leetcode.com/problems/valid-perfect-square/ Very Easy
• https://www.geeksforgeeks.org/find-rotation-count-rotated-sorted-array/ Easy
• https://leetcode.com/problems/median-of-two-sorted-arrays/ Hard
• https://leetcode.com/problems/maximum-candies-allocated-to-k-children/ Medium
• https://leetcode.com/problems/successful-pairs-of-spells-and-potions/ Medium
• https://leetcode.com/problems/count-number-of-rectangles-containing-each-point/ Medium
• https://leetcode.com/problems/powx-n/ Medium
• https://leetcode.com/problems/capacity-to-ship-packages-within-d-days/ Medium
• https://leetcode.com/problems/minimized-maximum-of-products-distributed-to-any-store/ Medium
• https://leetcode.com/problems/my-calendar-i/ Medium
• https://leetcode.com/problems/median-of-two-sorted-arrays/ Hard
• https://leetcode.com/problems/maximum-count-of-positive-integer-and-negative-integer/ Easy

Sorting

• BubbleSort

• CustomSort

  • https://leetcode.com/problems/matrix-cells-in-distance-order/ Easy
  • https://leetcode.com/problems/sort-the-jumbled-numbers/ Medium
  • https://leetcode.com/problems/kth-largest-element-in-a-stream/ Easy
  • https://leetcode.com/problems/find-closest-number-to-zero/ Easy
  • https://leetcode.com/problems/sort-array-by-parity/ Easy
  • https://leetcode.com/problems/missing-number/ Easy
  • https://leetcode.com/problems/sender-with-largest-word-count/ Medium Array
  • https://leetcode.com/problems/maximum-total-importance-of-roads/ Medium
  • https://leetcode.com/problems/top-k-frequent-words/ Medium
  • https://leetcode.com/problems/queue-reconstruction-by-height/ Medium
  • https://leetcode.com/problems/sort-characters-by-frequency/ Medium
  • https://leetcode.com/problems/delete-greatest-value-in-each-row/ Easy
  • https://leetcode.com/problems/longest-square-streak-in-an-array/ Medium
  • https://leetcode.com/problems/sort-the-students-by-their-kth-score/ Medium
  • https://leetcode.com/problems/custom-sort-string/ Medium
  • https://leetcode.com/problems/neither-minimum-nor-maximum/ Medium
  • https://leetcode.com/problems/sort-vowels-in-a-string/description/ Medium

• CycleSort

  • https://leetcode.com/problems/missing-number/ Easy
  • https://leetcode.com/problems/set-mismatch/ ```Easy`https://leetcode.com/problems/majority-element-ii/``
  • https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/ Easy
  • https://leetcode.com/problems/find-the-duplicate-number/ Medium
  • https://leetcode.com/problems/find-all-duplicates-in-an-array/ Medium

• InsertionSort

• SelectionSort

Stack

• https://leetcode.com/problems/daily-temperatures/ Medium
• https://leetcode.com/problems/min-stack/ Easy
• https://leetcode.com/problems/backspace-string-compare/ Easy
• https://leetcode.com/problems/implement-stack-using-queues/ Easy
• https://leetcode.com/problems/valid-parentheses/ Easy
• https://leetcode.com/problems/next-greater-element-i/ Easy
• https://www.interviewbit.com/problems/nearest-smaller-element/# Easy
• https://practice.geeksforgeeks.org/problems/sort-a-stack/1 Easy
• https://leetcode.com/problems/increasing-order-search-tree/ Medium
• https://leetcode.com/problems/largest-rectangle-in-histogram/ Hard Recommended
• https://leetcode.com/problems/minimum-add-to-make-parentheses-valid/ Medium
• https://leetcode.com/problems/maximal-rectangle/ Hard
• https://leetcode.com/problems/is-subsequence/ Easy
• https://leetcode.com/problems/remove-k-digits/ Medium Recommended
• https://leetcode.com/problems/score-of-parentheses/ Medium
• https://leetcode.com/problems/minimum-remove-to-make-valid-parentheses/ Medium
• https://leetcode.com/problems/simplify-path/ Medium
• https://leetcode.com/problems/validate-stack-sequences/ Medium
• https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string-ii/ Medium
• https://leetcode.com/problems/132-pattern/ Medium
• https://leetcode.com/problems/flatten-nested-list-iterator/ Medium
• https://leetcode.com/problems/remove-all-adjacent-duplicates-in-string/ Easy
• https://leetcode.com/problems/steps-to-make-array-non-decreasing/ Medium
• https://leetcode.com/problems/maximum-product-of-word-lengths/ Medium
• https://leetcode.com/problems/minimum-deletions-to-make-array-beautiful/ Medium
• https://leetcode.com/problems/construct-smallest-number-from-di-string/ Medium
• https://leetcode.com/problems/longest-absolute-file-path/ Medium
• https://leetcode.com/problems/removing-stars-from-a-string/ Medium
• https://leetcode.com/problems/maximum-binary-tree/ Medium
• https://leetcode.com/problems/make-the-string-great/ Easy
• https://leetcode.com/problems/online-stock-span/ Medium
• https://leetcode.com/problems/basic-calculator-ii/ Medium
• https://leetcode.com/problems/validate-stack-sequences/ Medium
• https://leetcode.com/problems/decode-string/ Medium
• https://leetcode.com/problems/reveal-cards-in-increasing-order/ Medium
• https://leetcode.com/problems/minimum-string-length-after-removing-substrings/ Easy

Strings

• https://leetcode.com/problems/adding-spaces-to-a-string/ Medium
• https://leetcode.com/problems/matchsticks-to-square/ Medium
• https://leetcode.com/problems/find-substring-with-given-hash-value/ Medium Recommended
• https://leetcode.com/problems/find-the-difference/ ```Easy``
• https://leetcode.com/problems/longest-palindrome-by-concatenating-two-letter-words/ Medium
• https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-anagram-ii/ Easy
• https://leetcode.com/problems/permutation-in-string/ Medium
• https://leetcode.com/problems/robot-bounded-in-circle/ Medium Recommended
• https://leetcode.com/problems/string-to-integer-atoi/ Medium Recommended
• https://leetcode.com/problems/word-pattern/ Easy
• https://leetcode.com/problems/cells-in-a-range-on-an-excel-sheet/ Easy
• https://leetcode.com/problems/maximum-repeating-substring/ Easy
• https://leetcode.com/problems/binary-watch/ Easy
• https://leetcode.com/problems/reverse-string/ Easy
• https://leetcode.com/problems/valid-palindrome-ii/ Easy
• https://leetcode.com/problems/compare-strings-by-frequency-of-the-smallest-character/ Medium
• https://leetcode.com/problems/zigzag-conversion/ Medium
• https://leetcode.com/problems/count-prefixes-of-a-given-string/ Easy
• https://leetcode.com/problems/find-resultant-array-after-removing-anagrams/submissions/ Easy
• https://leetcode.com/problems/check-if-number-has-equal-digit-count-and-digit-value/ Easy
• https://leetcode.com/problems/contains-duplicate/ Easy
• https://leetcode.com/problems/rearrange-characters-to-make-target-string/ Easy
• https://leetcode.com/problems/find-common-characters/ Easy
• https://leetcode.com/problems/remove-palindromic-subsequences/ Easy
• https://leetcode.com/problems/strong-password-checker-ii/ Easy
• https://leetcode.com/problems/number-of-segments-in-a-string/ Easy
• https://leetcode.com/problems/string-without-aaa-or-bbb/ Medium
• https://leetcode.com/problems/search-suggestions-system/ Medium
• https://leetcode.com/problems/short-encoding-of-words/ Medium
• https://leetcode.com/problems/greatest-english-letter-in-upper-and-lower-case/ Easy
• https://leetcode.com/problems/unique-morse-code-words/ Easy
• https://leetcode.com/problems/count-asterisks/ Easy
• https://leetcode.com/problems/valid-anagram/ Easy
• https://leetcode.com/problems/longest-ideal-subsequence/ Medium
• https://leetcode.com/problems/first-unique-character-in-a-string/ Easy
• https://leetcode.com/problems/minimum-recolors-to-get-k-consecutive-black-blocks/ Easy
• https://leetcode.com/problems/isomorphic-strings/ Easy
• https://leetcode.com/problems/check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence/ Easy
• https://leetcode.com/problems/maximum-number-of-vowels-in-a-substring-of-given-length/ Medium
• https://leetcode.com/problems/longest-palindrome/ Easy
• https://leetcode.com/problems/strong-password-checker/ Hard
• https://leetcode.com/problems/reverse-words-in-a-string/ Medium
• https://leetcode.com/problems/reverse-vowels-of-a-string/ Easy
• https://leetcode.com/problems/determine-if-string-halves-are-alike/ Easy
• https://leetcode.com/problems/circular-sentence/ Easy
• https://leetcode.com/problems/maximum-value-of-a-string-in-an-array/ Easy
• https://leetcode.com/problems/count-pairs-of-similar-strings/ Easy
• https://leetcode.com/problems/greatest-common-divisor-of-strings/ Easy
• https://leetcode.com/problems/defanging-an-ip-address/ Easy
• https://leetcode.com/problems/find-the-longest-balanced-substring-of-a-binary-string/ Easy
• https://leetcode.com/problems/delete-characters-to-make-fancy-string/ Easy
• https://leetcode.com/problems/repeated-substring-pattern/ Easy
• https://leetcode.com/problems/find-the-width-of-columns-of-a-grid/ Easy
• https://leetcode.com/problems/minimum-additions-to-make-valid-string/ Easy
• https://leetcode.com/problems/merge-strings-alternately/ Easy
• https://leetcode.com/problems/lexicographically-smallest-palindrome/ Easy
• https://leetcode.com/problems/minimize-string-length/ Easy
• https://leetcode.com/problems/check-if-a-string-is-an-acronym-of-words/ Easy
• https://leetcode.com/problems/minimum-number-of-pushes-to-type-word-i/ Easy

Trees

• https://leetcode.com/problems/insert-into-a-binary-search-tree/ Medium
• https://leetcode.com/problems/all-elements-in-two-binary-search-trees/ Medium
• https://leetcode.com/problems/convert-bst-to-greater-tree/ Medium
• https://leetcode.com/problems/recover-binary-search-tree/ Medium
• https://leetcode.com/problems/kth-smallest-element-in-a-bst/ Medium
• https://leetcode.com/problems/maximum-depth-of-binary-tree/ Easy
• https://leetcode.com/problems/minimum-depth-of-binary-tree/ Easy
• https://leetcode.com/problems/diameter-of-binary-tree/ Easy
• https://leetcode.com/problems/count-complete-tree-nodes/ Medium
• https://leetcode.com/problems/binary-tree-right-side-view/ Medium
• https://leetcode.com/problems/balanced-binary-tree/ Easy
• https://leetcode.com/problems/remove-duplicates-from-sorted-array/ Medium
• https://leetcode.com/problems/binary-tree-inorder-traversal/ Easy
• https://leetcode.com/problems/populating-next-right-pointers-in-each-node/ Medium
• https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/ Medium
• https://leetcode.com/problems/count-complete-tree-nodes/ Medium
• https://leetcode.com/problems/search-in-a-binary-search-tree/ Easy
• https://leetcode.com/problems/root-equals-sum-of-children/ Easy
• https://leetcode.com/problems/same-tree/ Easy
• https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/ Easy
• https://leetcode.com/problems/symmetric-tree/ Easy
• https://leetcode.com/problems/increasing-order-search-tree/ Easy
• https://leetcode.com/problems/binary-search-tree-iterator/ Medium
• https://leetcode.com/problems/validate-binary-search-tree/ Medium
• https://leetcode.com/problems/two-sum-iv-input-is-a-bst/ Easy
• https://leetcode.com/problems/network-delay-time/ Medium
• https://leetcode.com/problems/deepest-leaves-sum/ Medium
• https://leetcode.com/problems/find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree/ Medium
• https://leetcode.com/problems/critical-connections-in-a-network/ Hard
• https://leetcode.com/problems/binary-tree-preorder-traversal/ Easy
• https://leetcode.com/problems/n-ary-tree-preorder-traversal/ Easy
• https://leetcode.com/problems/minimum-depth-of-binary-tree/ Easy
• https://leetcode.com/problems/binary-tree-level-order-traversal/ Medium
• https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/ Medium
• https://leetcode.com/problems/min-cost-to-connect-all-points/ Medium
• https://leetcode.com/problems/binary-tree-cameras/ Hard
• https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree/ Hard
• https://leetcode.com/problems/invert-binary-tree/ Easy
• https://leetcode.com/problems/maximum-width-of-binary-tree/ Medium
• https://leetcode.com/problems/even-odd-tree/ Medium
• https://leetcode.com/problems/find-largest-value-in-each-tree-row/ Medium
• https://leetcode.com/problems/binary-tree-tilt/ Easy
• https://leetcode.com/problems/path-sum/ Easy
• https://leetcode.com/problems/path-sum-ii/ Medium
• https://leetcode.com/problems/path-sum-iii/ Medium
• https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal/ Medium
• https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/ Medium
• https://leetcode.com/problems/construct-string-from-binary-tree/ Easy
• https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/ Medium
• https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/ Medium
• https://leetcode.com/problems/count-good-nodes-in-binary-tree/ Medium
• https://leetcode.com/problems/n-ary-tree-level-order-traversal/ Medium
• https://leetcode.com/problems/binary-tree-pruning/ Medium
• https://leetcode.com/problems/balance-a-binary-search-tree/ Medium
• https://leetcode.com/problems/maximum-binary-tree-ii/ Medium
• https://leetcode.com/problems/pseudo-palindromic-paths-in-a-binary-tree/ Medium
• https://leetcode.com/problems/most-frequent-subtree-sum/ Medium
• https://leetcode.com/problems/add-one-row-to-tree/ Medium
• https://leetcode.com/problems/two-sum-iv-input-is-a-bst/ Easy
• https://leetcode.com/problems/delete-leaves-with-a-given-value/ Medium
• https://leetcode.com/problems/leaf-similar-trees/ Easy
• https://leetcode.com/problems/maximum-product-of-splitted-binary-tree/ Medium
• https://leetcode.com/problems/binary-tree-maximum-path-sum/ Hard
• https://leetcode.com/problems/sum-root-to-leaf-numbers/ Medium
• https://leetcode.com/problems/delete-nodes-and-return-forest/ Medium
• https://leetcode.com/problems/kth-largest-sum-in-a-binary-tree/ Medium
• https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree/ Medium
• https://leetcode.com/problems/check-completeness-of-a-binary-tree/ Medium
• https://leetcode.com/problems/binary-tree-level-order-traversal-ii/ Medium
• https://leetcode.com/problems/cousins-in-binary-tree-ii/ Medium
• https://leetcode.com/problems/cousins-in-binary-tree/ Easy
• https://leetcode.com/problems/make-costs-of-paths-equal-in-a-binary-tree/ Medium
• https://leetcode.com/problems/find-elements-in-a-contaminated-binary-tree/ Medium

Tries

• https://leetcode.com/problems/design-add-and-search-words-data-structure/ Medium
• https://leetcode.com/problems/camelcase-matching/ Medium
• https://leetcode.com/problems/longest-word-in-dictionary/ Medium
• https://leetcode.com/problems/short-encoding-of-words/ Medium
• https://leetcode.com/problems/replace-words/description/ Medium
• https://leetcode.com/problems/sum-of-prefix-scores-of-strings/ Hard
• https://leetcode.com/problems/implement-trie-prefix-tree/ Medium
• https://leetcode.com/problems/implement-magic-dictionary/ Medium

Two Pointers

• https://leetcode.com/problems/push-dominoes/ Medium
• https://leetcode.com/problems/string-compression/ Medium
• https://leetcode.com/problems/valid-triangle-number/ Medium
• https://leetcode.com/problems/append-characters-to-string-to-make-subsequence/ Medium
• https://leetcode.com/problems/count-subarrays-with-fixed-bounds/ Hard
• https://leetcode.com/problems/repeated-dna-sequences/ Medium
• https://leetcode.com/problems/assign-cookies/ Easy
• https://leetcode.com/problems/number-of-adjacent-elements-with-the-same-color/ Medium
• https://leetcode.com/problems/longest-subarray-of-1s-after-deleting-one-element/ Medium
• https://leetcode.com/problems/unique-length-3-palindromic-subsequences/ Easy

Concepts

- Print Number from 1 to N && from N to 1 && from 1 to N and N to 1 in same - Sum and Product of Digits in a Number - Reverse A Number - Maximize The Number By Swapping Adjacent Two Digits ```Not Yet Solved```

• dynamic Programming

  • Print possible Sum for Target using given number as many times possible
  • Longest Common Subsequence
  • Printing Longest Common Subsequence

• binarySearch

  • Order Agnostic Binary Search Binary Search
  • Search in Infinite Array Binary Search
  • Find Binary Search Ceiling Value Binary Search
  • Find Binary Search Floor ValueBinary Search
  • Find Pivot in Rotated Sorted Array Binary Search
  • Find Pivot in Rotated Sorted Element with Duplicates Binary Search
  • Rotation Count for Rotated Array Binary Search
  • Search in Sorted Row and Column Wise Matrix Binary Search
  • Search a Matrix sorted Row and Column wise Binary Search , Matrix
  • Search a Sorted Matrix Binary Search , Matrix

• overflow & underflow

  • String to Integer - Handling Integer Overflow and Underflow

• graphs

  • Graph Representation
  • BFS
  • DFS
  • Cycle Detection Using BFS
  • Cycle Detection Using DFS
  • Cycle Detection Using BFS in DAG
  • Cycle Detection Using DFS in DAG
  • Topological Sort (Linear Ordering of Vertices such that if there is and edge u --> v, u appears before v in that ordering )

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