https://leetcode.com/problems/minimum-number-of-steps-to-make-two-strings-
anagram
1347. Minimum Number of Steps to Make Two Strings Anagram
给两个长度相同的字串s和t，每次可以从t选一个字符换成其他字，求把t变成s的最小次数
只要包含的字符相同就好，顺序可以不同(Anagram)。
Example 1:
Input: s = "bab", t = "aba"
Output: 1
Explanation: Replace the first 'a' in t with b, t = "bba" which is anagram of s.
Example 2:
Input: s = "leetcode", t = "practice"
Output: 5
Explanation: Replace 'p', 'r', 'a', 'i' and 'c' from t with proper characters
to make t anagram of s.
Example 3:
Input: s = "anagram", t = "mangaar"
Output: 0
Explanation: "anagram" and "mangaar" are anagrams.
Python3 Code：