题解

#include<bits/stdc++.h>
using namespace std;
char a[55];
int main()
{
    cin >> a;
    for(int i = 0; i < strlen(a); i++)
    {
        if(a[i] >= 'A' && a[i] <= 'Z')
        {
            a[i] = (a[i] - 'A' + 3) % 26 + 'A' + 32;
        }
        else if(a[i] >= 'a' && a[i] <= 'z')
        {
            a[i] = (a[i] - 'a' + 3) % 26 + 'a' - 32;
        }
    }
    for(int i = strlen(a) - 1; i >= 0; i--)
    {
        cout << a[i];
    }
    return 0;
}