原题传送门

1. 题目描述

2. Solution

import sys

if sys.platform != "linux":
    sys.stdin = open("input/HJ102.txt")


def solve(s):
    from collections import Counter, defaultdict
    res = Counter(s).most_common()
    cnt_group = defaultdict(list)
    for c, cnt in res:
        cnt_group[cnt].append(c)
    for cnt, c_group in cnt_group.items():
        c_group.sort()
        [print(x, end="") for x in c_group]
    print()


for line in sys.stdin:
    s = line.strip()
    solve(s)

标签：defaultdict,cnt,group,res,print,sys,牛客,HJ102,机试
来源： https://www.cnblogs.com/junstat/p/16181410.html