https://www.hackerrank.com/interview/interview-preparation-kit/strings/challenges 아.. 또 노가다로 푼거 같다. #!/bin/python3 import math import os import random import re import sys # Complete the isValid function below. def isValid(s): diff = {} for i in s: if i not in diff: diff[i] = 1 else: diff[i] += 1 print(diff) a = sorted([i for i in diff.values()]) l = len(a) if a[0] == a[l-1]: return "YES" elif a..