题解 | #字符串排序#

import sys
from collections import deque

str1 =input()
s = list(str1)
n = len(s)
t = 65
list1=[]
list2 = [""] * n
flag = [True] * n
for i in range(0, n):
    if not s[i].isalpha():
        list2[i] = s[i]
        flag[i] = False
i = 0
while t <= 90:
    for i in range(0, n):
        if flag[i] == False:
            i += 1
            continue
        if flag[i] == True:
            if ord(s[i]) == t or ord(s[i]) == t + 32:
                list1.append(s[i])
    t += 1

list3=deque(list1)
for i in range(0,n):
    if flag[i]==True:
        print(list3.popleft(),sep="",end="")
    if flag[i] == False:
        print(list2[i],sep="",end="")

设置了一个flag 数组，用来判断位置是否被填充过