Program for Counting Sort

def countSort(arr):

output = [0 for i in range(256)]

count = [0 for i in range(256)]

ans = ["" for _ in arr]

for i in arr:

count[ord(i)] += 1

for i in range(256):

count[i] += count[i-1]

for i in range(len(arr)):

output[count[ord(arr[i])]-1] = arr[i]

count[ord(arr[i])] -= 1

for i in range(len(arr)):

ans[i] = output[i]

return ans

arr = "Pythonforengineers"

ans = countSort(arr)

print ("Sorted character array is %s" %("".join(ans)))