# 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]),