题解 | #MP3光标位置#

#include <iostream>
#include <random>
#include <string>
#include <sys/types.h>
#include <vector>
using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int> m(n);
    for(int i=0;i<n;++i)
        m[i]=i+1;
    int cusor=0;
    int first=0;
    string s;
    cin >> s;
    for(char ch:s){
        if(ch=='U'){
            if(cusor==0){
                cusor=n-1;
                if(n>4){
                    first=cusor-3;
                }
            }
            else{
                --cusor;
                if(n>4&&cusor<first)
                    first=cusor;
            }    
        }
        else {
            if(cusor==n-1){
                cusor=0;
                if(n>4)
                    first=0;
            }
            else {
                ++cusor;
                if(n>4&&cusor>first+3)
                    first++;
            }
        }
    }
    for(int i=first;i<min(first+4,n);++i)
        cout << m[i] << ' ';
    cout << endl;
    cout << m[cusor];
}
// 64 位输出请用 printf("%lld")