题解 | #字符串加解密#

#include<bits/stdc++.h>

using namespace std;
string encode(string str);
string decode(string str);
int main(){
    
    string str1,str2;
    while(cin>>str1>>str2){
        string res1 =  encode(str1);
        string res2 = decode(str2);
        cout<<res1<<endl;
        cout<<res2<<endl;
    }
    return 0;
}

string encode(string str){
    string res="";
    for(int i=0;i<str.size();++i){
        if(str[i]=='z'){
            res.push_back('A');
            continue;
        }
        if(str[i]=='Z'){
            res.push_back('a');
            continue;
        }
        if(str[i]>='a'&&str[i]<'z'){
            char ch = str[i]+1;
            res.push_back(toupper(ch));
        }else if(str[i]>='A'&&str[i]<='Z'){
            char ch = str[i]+1;
            res.push_back(tolower(ch));
        }else if(str[i]=='9')
            res.push_back('0');
        else if(str[i]>='0'&&str[i]<='8')
            res.push_back(str[i]+1);
        else
            res.push_back(str[i]);
    }
    return res;
}

string decode(string str){
    string res="";
    for(int i=0;i<str.size();++i){
        if(str[i]=='A'){
            res.push_back('z');continue;
        }
        if(str[i]=='a'){
            res.push_back('Z');continue;
        }
        if(str[i]>'a'&&str[i]<='z'){
            char ch = str[i]-1;
            res.push_back(toupper(ch));
        }else if(str[i]>'A'&&str[i]<='Z'){
            char ch = str[i]-1;
            res.push_back(tolower(ch));
        }else if(str[i]=='0')
            res.push_back('9');
        else if(str[i]>'0'&&str[i]<='9')
            res.push_back(str[i]-1);
        else
            res.push_back(str[i]);
    }
    return res;
}