Merge pull request #8 from ratanboddu/facebook-sequence

Adding Solution for facebook-LongestSequenceWithTwoUniqueNumbers
emafazillah · Oct 31, 2020 · 3f92034 · 3f92034
2 parents 24192ce + bb270a6
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diff --git a/README.md b/README.md
@@ -21,7 +21,7 @@ Number of Ways to Climb Stairs | LinkedIn | [ClimbingStairs.java](https://github
 Find Pythagorean Triplets | Uber | [FindPythagoreanTriplets.java](https://github.com/emafazillah/DailyInterviewProJava/blob/master/src/main/java/com/dailyinterviewprojava/uber/FindPythagoreanTriplets.java) | Done |
 Edit Distance | Airbnb | [EditDistance.java](https://github.com/emafazillah/DailyInterviewProJava/blob/master/src/main/java/com/dailyinterviewprojava/airbnb/EditDistance.java) | To Do |
 Create a Simple Calculator | Google | [CreateASimpleCalculator.java](https://github.com/emafazillah/DailyInterviewProJava/blob/master/src/main/java/com/dailyinterviewprojava/google/CreateASimpleCalculator.java) | Done |
-Longest Sequence with Two Unique Numbers | Facebook | [LongestSequenceWithTwoUniqueNumbers.java](https://github.com/emafazillah/DailyInterviewProJava/blob/master/src/main/java/com/dailyinterviewprojava/facebook/LongestSequenceWithTwoUniqueNumbers.java) | To Do |
+Longest Sequence with Two Unique Numbers | Facebook | [LongestSequenceWithTwoUniqueNumbers.java](https://github.com/emafazillah/DailyInterviewProJava/blob/master/src/main/java/com/dailyinterviewprojava/facebook/LongestSequenceWithTwoUniqueNumbers.java) | Done |
 Find Cycles in a Graph | Facebook | [FindCyclesInAGraph.java](https://github.com/emafazillah/DailyInterviewProJava/blob/master/src/main/java/com/dailyinterviewprojava/facebook/FindCyclesInAGraph.java) | To Do |
 Word Search | Amazon | [WordSearch.java](https://github.com/emafazillah/DailyInterviewProJava/blob/master/src/main/java/com/dailyinterviewprojava/amazon/WordSearch.java) | Done |
 Minimum Size Subarray Sum | Amazon | [MinimumSizeSubarraySum.java](https://github.com/emafazillah/DailyInterviewProJava/blob/master/src/main/java/com/dailyinterviewprojava/amazon/MinimumSizeSubarraySum.java) | Done |

diff --git a/src/main/java/com/dailyinterviewprojava/facebook/LongestSequenceWithTwoUniqueNumbers.java b/src/main/java/com/dailyinterviewprojava/facebook/LongestSequenceWithTwoUniqueNumbers.java
@@ -11,6 +11,62 @@
  * The longest sequence that contains just 2 unique numbers is [3, 1, 3, 1]
  *
  */
+
+import java.util.Arrays;
+import java.util.Scanner;
+
+import com.dailyinterviewprojava.util.InputUtil;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
 public class LongestSequenceWithTwoUniqueNumbers {
 
+    static int findSequence(int[] numbers) {
+        if (numbers.length < 3) {
+            return numbers.length;
+        }
+
+
+        Map<Integer, Integer> unique = new HashMap<>();
+        int startIndex = 0;
+        int max = 0;
+
+        for (int i = 0; i < numbers.length; i++) {
+            int number = numbers[i];
+            if (!unique.containsKey(number)) {
+                unique.put(number, 0);
+            }
+            unique.put(number, unique.get(number) + 1);
+
+            if (unique.size() > 2) {
+                // shift "window"
+                while (unique.size() > 2) {
+                    int numberToDelete = numbers[startIndex];
+                    unique.replace(numberToDelete, unique.get(numberToDelete) - 1);
+                    if (unique.get(numberToDelete) == 0) {
+                        unique.remove(numberToDelete);
+                    }
+                    startIndex++;
+                }
+            } else {
+                // update max
+                max = Math.max(max, i - startIndex + 1);
+            }
+        }
+
+        return max;
+    }
+
+    public static void main(String[] args) {
+        // Input
+        Scanner scanner = new Scanner(System.in);
+        String[] inputs = InputUtil.inputArr(scanner.next());
+        int[] nums = InputUtil.integerArr(inputs);
+
+        // Calculate output
+        System.out.println(findSequence(nums));
+    }
 }