Be

Sorting/Merge Sort/Python/MergeSort.py

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+def merge(array: [int], beg: int, m: int, end: int):
+    temp = [0]* (end - beg + 1)
+    i,j,k = beg, m + 1, 0
+
+    while i <= m and j <= end:
+        if array[i] <= array[j]:
+            temp[k] = array[i]
+            k += 1
+            i += 1
+        else:
+            temp[k] = array[j]
+            k += 1
+            j += 1     
+
+    while i <= m:
+        temp[k] = array[i]
+        i += 1
+        k += 1
+
+    while j <= end:
+        temp[k] = array[j]
+        j += 1
+        k += 1      
+
+    for i in range(beg,end+1):
+        array[i] = temp[i - beg]      
+
+def Merge_sort(array: [int], beg: int, end: int):
+    if beg < end:
+        m = (beg + end)/2
+        Merge_sort(array,beg,m)
+        Merge_sort(array,m+1,end)
+        merge(array,beg,m,end)
+
+#Sample Input: 5 14 35 20 7 2
+#Sample Output: 2 5 7 14 20 35
+#Time Complexity: θ(nLogn) in all cases(worst, average and best)
+#Space Complexity: O(n)  

Sorting/Merge Sort/algorithm.md

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+## Merge Sort
+### Merge Sort is a very efficient sorting algorithm. It uses Divide and Conquer principle to sort the elements. It divides the list into two equal halves. The sub-lists are divided again and again until each sublist consists of a single element.Then merge sublists in a way that results in a sorted list.
+![This is an image](https://media.geeksforgeeks.org/wp-content/cdn-uploads/Merge-Sort-Tutorial.png)     
+
+## Algorithm
+```
+Merge_sort(array,start,end)
+Step 1: if start<end
+Step 2:set m = (start+end)/2
+Step 3: Merge_sort(array,start,m)
+Step 4: Merge_sort(array,m+1,end)
+Step 5: merge(array,start,m,end)
+Step 6: end of if
+Step 7: END of Merge_sort
+Step 8:Exit
+```

Traversal Algorithms/Tree Traversals/Preorder Traveral - Binary Tree/Python/PreorderTraversal.py

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+
+# Sample Input::
+# Input Tree :
+#   1
+#  / \
+# 6   5
+#    /
+#   2
+
+# Output: [1, 6, 5, 2]
+
+# Recursive Code
+# Binary Tree representation
+# class TreeNode:
+
+#    def __init__(self,value):
+#        self.value = value
+#        self.left = None
+#        self.right = None
+
+def preorder(root):
+    res = []
+
+    preorderTraversal(root, res)
+    return res
+
+def preorderTraversal(root, res):
+
+    if root is None:
+        return 
+
+    res.append(root.value)
+
+    preorderTraversal(root.left, res)
+
+    preorderTraversal(root.right, res)
+
+    return
+
+# Time Complexity: O(n)
+# Space Complexity: O(n)
+
+
+
+