题解 | 删除公共字符

#include <iostream>
#include <bits/stdc++.h>
#include <unordered_set>
using namespace std;

int main() {
    string s1,s2;
    getline(cin,s1);
    getline(cin,s2);
    unordered_set<char> del_chars;
    for(char c1:s2){
        del_chars.insert(c1);
    }
    string result="";
    for(char c: s1){
        if(del_chars.find(c)==del_chars.end()){
            result+=c;
        }
    }
    cout << result << endl;
    return 0;
}
// 64 位输出请用 printf("%lld")