1347. Minimum Number of Steps to Make Two Strings Anagram

You are given two strings of the same length s and t. In one step you can choose any character of t and replace it with another character.

Return the minimum number of steps to make t an anagram of s.

An Anagram of a string is a string that contains the same characters with a different (or the same) ordering.

class Solution {
public:
    int minSteps(string s, string t) {
        unordered_map<char, int> freq;
        for(auto& ch : s) freq[ch]++;
        for(auto& ch : t) freq[ch]--;
        int res = 0;
        for(auto& [_, v] : freq) res += abs(v);
        return res / 2;
    }
};