AC代码如下

#include <bits/stdc++.h>
using namespace std;
int main()
{
    string s;
    getline(cin, s);
    int len = s.length();
    for (int i = 0; i < len; i++)
    {
        if (s[i] == 'z')
            s[i] = 'a';
        else if (s[i] >= 'a' && s[i] <= 'z')
            s[i]++;
    }
    cout << s;
    return 0;
}