計數排序不是比較排序,它的下屆也擺脫了比較排序O(nlgn)的限制,達到了O(n)
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
def COUTING_SORT(A):
i = 0;
# 這裏需要將使B的長度是A的長度加1,因爲在第一步時,記錄的位置每一個都往後移了一格
B = [0] * (len(A)+1)
C = [0] * (max(A)+1)
while i < len(A):
C[A[i]] = C[A[i]]+1
i += 1
i = 0;
while i < len(C)-1:
C[i+1] = C[i] + C[i+1]
i += 1
i = len(A) - 1
while i >= 0:
B[C[A[i]]] = A[i]
C[A[i]] -= 1
i -= 1
print(B)
A = [2,5,3,0,2,3,0,3]
COUTING_SORT(A)