题解 | 字符串加解密

//1.输入输出
//2.弄一个加密函数
//3.弄一个解密函数
//4.输出
#include<bits/stdc++.h>
using namespace std;
string jiami(string s){
    string result;
    for(int i = 0;i<s.size();i++){
        if(isalpha(s[i])){
            if(s[i] >= 'a' && s[i] <= 'z'){
            s[i] = ((s[i]) - 'a'+1)%26 + 'a';
            result.push_back(toupper(s[i]));
            }
            else{
                s[i] = ((s[i]) - 'A'+1)%26 + 'A';
            result.push_back(tolower(s[i]));
            }
        }
        else if(s[i] == '9'){
            s[i] = '0';
            result.push_back(s[i]);
        }
        else{
            s[i] = (s[i] - '0' + 1)%10 + '0';
            result.push_back(s[i]);
        }
    }
    return result;
}
string jiemi(string t){
    string result;
    for(int i = 0;i<t.size();i++){
        if(isalpha(t[i])){
            if(t[i] >='a' && t[i] <= 'z'){
            t[i] = ((t[i]) - 'a' -1 + 26)%26 + 'a';
            result.push_back(toupper(t[i]));
        }
        else{
            t[i] = (t[i] - 'A' -1 + 26)%26 + 'A';
            result.push_back(tolower(t[i]));
        }
        }
        else if(t[i] == '0'){
            t[i] = '9';
            result.push_back(t[i]);
        }
        else{
            t[i] = (t[i] - '0' -1 )%10 +'0';
            result.push_back(t[i]);
        }
    }
    return result;
}
int main(){
    string s;
    cin >> s;
    string t;
    cin >> t;
    cout << jiami(s) << endl;
    cout << jiemi(t) << endl;
    return 0;
}