Python 计数排序

减少循环次数参考:

def countSort(arr):

  count =[0for i in range(256)]

  output =[""for _ in arr]

  mx, mn =0,255

  for i in arr:

     idx = ord(i)

     if idx > mx: mx = idx

     if idx < mn: mn = idx

     count[idx]+=1

  idx =0

  for i in range(mn, mx +1):

     if count[i]==0:continue

     for _ in range(count[i]):

        output[idx]= chr(i)

        idx +=1

  return output

arr ="wwwrunoobcom"

ans = countSort(arr) 

print("字符数组排序 %s"  %("".join(ans)))