Cocktail Sort

Python program for implementation of Cocktail Sort.

Cocktail Sort

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+# 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]), 
+
+
+#output
+#Sorted array is: 0 1 2 2 4 5 8