题解 | #字符串加密#

#include <iostream>
#include <vector>
using namespace std;

bool isUpperCase(char c){
    return c >= 'A' && c <= 'Z';
}

int main() {
    string key, s;
    while (cin >> key >> s) {
        vector<char> alphabet(26, '0');
        vector<bool> vis(26, false);
        int j = 0;
        for(int i = 0; i < key.size(); i++){
            if(!vis[key[i] - 'a']){
                alphabet[j++] = key[i];
                vis[key[i] - 'a'] = true;
            }
        }
        char c = 'a';
        while(c <= 'z' && j < 26){
            if(vis[c - 'a']) {
                c++;
                continue;
            }
            alphabet[j++] = c++;
        }

        string ans;
        for(char c: s){
            ans += alphabet[c - 'a'];
        }
        cout << ans << endl;
    }
    return 0;
}
// 64 位输出请用 printf("%lld")

构建字母表