Cocktail_Sort.py

# GitHub username: grvkr777 (Gaurav Kar)
# Python program for implementation of Cocktail Sort 
  
def cocktailSort(a): 
    n = len(a) 
    swapped = True
    start = 0
    end = n-1
    while (swapped == True): 
  
        # reset the swapped flag on entering the loop, 
        # because it might be true from a previous 
        # iteration. 
        swapped = False
  
        # loop from left to right same as the bubble 
        # sort 
        for i in range (start, end): 
            if (a[i] > a[i + 1]) : 
                a[i], a[i + 1]= a[i + 1], a[i] 
                swapped = True
  
        # if nothing moved, then array is sorted. 
        if (swapped == False): 
            break
  
        # otherwise, reset the swapped flag so that it 
        # can be used in the next stage 
        swapped = False
  
        # move the end point back by one, because 
        # item at the end is in its rightful spot 
        end = end-1
  
        # from right to left, doing the same 
        # comparison as in the previous stage 
        for i in range(end-1, start-1, -1): 
            if (a[i] > a[i + 1]): 
                a[i], a[i + 1] = a[i + 1], a[i] 
                swapped = True
  
        # increase the starting point, because 
        # the last stage would have moved the next 
        # smallest number to its rightful spot. 
        start = start + 1
  
# Driver code to test above 
a = [5, 1, 4, 2, 8, 0, 2] 
cocktailSort(a) 
print("Sorted array is:") 
for i in range(len(a)): 
    print ("% d" % a[i]),