题解 | #MP3光标位置#

#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

int main() {
    int num;
    int curPos = 1;
    string  command;
    cin >> num >> command;
    int winBegin = 1;
    int winEnd = min(num, 4);
    
    for(int i = 0; i < command.length(); i++){
        if(command[i] == 'U') curPos = (curPos - 2 + num) % num + 1;
        if(command[i] == 'D') curPos = curPos % num + 1;
        
        if(winBegin > curPos){//特殊翻页D和一般翻页U
            winBegin = curPos;
            winEnd = winBegin + 3;
        }
        if(winEnd < curPos){//特殊翻页U和一般翻页D
            winEnd = curPos;
            winBegin = winEnd - 3;
        }
    }
    for(int i = winBegin; i <= winEnd; i++) cout << i << " ";
    cout  << endl;
    cout << curPos << endl;
    return 0;
}