代码如下：

#include<iostream>
#define max 100005
using namespace std;
char a[max],m[30]=" abcdefghijklmnopqrstuvwxyz";
int p=0,ca=0,fx=1;
string t;
void p_bian(){
    if(p==26&&fx==1)
        p=1;
    else if(p==1&&fx==-1)
        p=26;
    else p+=fx;
    return;
}
int main()
{
    int f;
    cin>>f;
    for(int i=1; i<=f; i++){
        cin>>t;
        if(t=="SMJER"){
            int n;
            cin>>n;
            while(ca<=n){
                a[ca++]=m[p];
                if(ca==n)
                    break;
                p_bian();
            }
            fx=-fx;
            p_bian();
            p_bian();
        }
        else if(t=="UPIT"){
            int n;
            char x;
            cin>>n>>x;
            while(ca<=n){
                a[ca++]=m[p];
                p_bian();
            }
            int sum=0;
            for(int j=1; j<=n; j++)
                if(a[j]==x)
                    sum++;
            cout<<sum<<endl;
        }
        /*for(int j=1; j<=ca; j++)
            cout<<a[j]<<" ";
        cout<<endl;*/
    }
    return 0;
}

评测记录