*B1093 字符串A B

题目：https://pintia.cn/problem-sets/994805260223102976/problems/1071785884776722432

代码

#include<string>
#include<cstdio>
#include<iostream>
using namespace std;
int main(){
    int hash[256] = {0};
    string a, b, s;
    getline(cin, a);
    getline(cin, b);
    s = a + b;
    for(int i = 0; i < s.size(); i++){
        if(hash[s[i]] == 0) cout<<s[i];
        hash[s[i]] = 1;
    }
    return 0;
}