题解 | #字符串排序#

import sys

for line in sys.stdin.readlines():
    letters = {}
    for i in range(26):
        letters[chr(ord('a')+i)] = []
    others = []
    li = list(line.strip())
    for i in range(len(li)):
        c = li[i]
        if c.lower() in letters:
            letters[c.lower()].append(c)
        else:
            others.append((i, c))
    ret = []
    for i in range(26):
        c = chr(ord('a') + i)
        ret.extend(letters[c])
    for i, c in others:
        ret.insert(i, c)
    print(''.join(ret))