Mergesort.py

# Python program for implementation of  
# MergeSort (Alternative) 
  
def merge_sort(values): 
  
    if len(values)>1: 
        m = len(values)//2
        left = values[:m] 
        right = values[m:] 
        left = merge_sort(left) 
        right = merge_sort(right) 
  
        values =[] 
  
        while len(left)>0 and len(right)>0: 
            if left[0]<right[0]: 
                values.append(left[0]) 
                left.pop(0) 
            else: 
                values.append(right[0]) 
                right.pop(0) 
  
        for i in left: 
            values.append(i) 
        for i in right: 
            values.append(i) 
                  
    return values 
  
# Input list 
a = [12, 11, 13, 5, 6, 7] 
print("Given array is") 
print(*a) 
  
a = merge_sort(a) 
  
# Print output 
print("Sorted array is : ") 
print(*a)