已经通过蓝桥杯 AC
#include<bits/stdc++.h>
#include<iostream>
using namespace std;
main()
{
string s;
cin>>s;
int a;
a=s.length();
for(int i=0;i<a;i++)
{
if(s[i]=='Z')
{
s[i]='a';
continue;
}
if(s[i]=='z')
{
s[i]='A';
continue;
}
if((s[i]<'z'&&s[i]>='a')||(s[i]>='A'&&s[i]<'Z'))
{
s[i]=s[i]+1;
}
}
cout<<s;
}