Merge pull request #30 from anubhav823/MergeSort

Added MergeSort

Sorting_Searching/mergeSort.py

@@ -0,0 +1,37 @@
+
+# -*- coding: utf-8 -*-
+def mergeSort(array):
+    if len(array)>1:
+
+        #dividing array into 2 parts
+        middle=len(array)//2
+        leftArray=array[:middle]
+        rightArray=array[middle:]
+
+        #recursively calling MergeSort
+        mergeSort(leftArray)
+        mergeSort(rightArray)
+
+        #3 variables for copying the sorted values into final array
+        i=j=k=0
+        #copying into final array
+        while i<len(leftArray) and j<len(rightArray):
+            if leftArray[i]<rightArray[j]:
+                array[k]=leftArray[i]
+                i+=1
+            else:
+                array[k]=rightArray[j]
+                j+=1
+            k+=1
+
+        #checking for any elements still left
+        while i<len(leftArray):
+            array[k]=leftArray[i]
+            i+=1
+            k+=1
+
+        while j<len(rightArray):
+            array[k]=rightArray[j]
+            j+=1
+            k+=1
+