题解 | #MP3光标位置#

import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextLine()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            in.nextLine();
            String str = in.nextLine();
            int[] arr = new int[2];
            if (n < 4) {
                arr[0] = 1;
                arr[1] = n;
            }else {
                arr[0] = 1;
                arr[1] = 4;
            }
            
            int now = 1;//当前所指向的歌曲序号
            for (int i = 0; i < str.length(); i++) {
                if (str.charAt(i) == 'U') {
                    now--;
                    if (now == 0) {
                        now = n;
                    }
                } else {
                    now++;
                    if (now == n + 1) {
                        now = 1;
                    }
                }
                if (now <= arr[0] && now >= arr[1]) {
                    continue;
                } else if (now > arr[1]) {
                    arr[1] = now;
                    arr[0] = now - 3;
                } else if (now < arr[0]) {
                    arr[0] = now;
                    arr[1] = now + 3;
                }
            }
            for (int m = 0; m < arr[1]-arr[0]+1; m++) {
                System.out.print((arr[0] + m) + " ");
            }
            System.out.println();
            System.out.println(now);
        }
    }
}