题解 | #MP3光标位置#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt(); // 歌曲的数量
        String operatorSequence = sc.next();
        int[] window = null;// 当前窗口
        int pointer = 0;//初始化指针
        if (n < 0) return;
        else if (n == 1) {
            System.out.println(1);
            System.out.println(1);
            return;
        } else if (n <= 4) {
            window = new int[n];
            for (int i = 0; i < n; i++) window[i] = i + 1; //装填窗口
            String[] operators = operatorSequence.split("");
            for (String operator : operators) {
                if (operator.equals("U")) {
                    if (pointer == 0) pointer = window.length - 1;
                    else pointer--;
                }
                if (operator.equals("D")) {
                    if (pointer == window.length - 1) pointer = 0;
                    else pointer++;
                }
            }
        } else {
            window = new int[4];
            for (int i = 0; i < 4; i++) window[i] = i + 1; //装填窗口
            String[] operators = operatorSequence.split("");
            for (String operator : operators) {
                if (operator.equals("U")) {
                    if (pointer == 0) {
                        if (window[pointer] == 1) {
                            //重新装填窗口
                            for (int j = 0; j < 4; j++) window[j] = n - (3 - j);
                            pointer = 3;
                        } else for (int j = 0; j < 4; j++) window[j] -= 1;
                    } else pointer--;
                }
                if (operator.equals("D")) {
                    if (pointer == 3) {
                        if (window[pointer] == n) {
                            //重新装填窗口
                            for (int j = 0; j < 4; j++) window[j] = j + 1;
                            pointer = 0;
                        } else for (int j = 0; j < 4; j++) window[j] += 1;
                    } else pointer++;
                }
            }
        }
        for (int i = 0; i < window.length; i++) {
            if (i != window.length - 1) System.out.print(window[i] + " ");
            else System.out.println(window[i]);
        }
        System.out.println(window[pointer]);
    }
}