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.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt(), cur = 0, start = cur, size = Math.min(n, 4);
            for (char c : in.next().toCharArray()) {
                switch (c) {
                    case 'U':
                        cur = (cur - 1 + n) % n;
                        break;
                    case 'D':
                        cur = (cur + 1 + n) % n;
                        break;
                }
                if (cur < start) {
                    start = cur;
                } else if (cur >= start + size) {
                    start = cur - size + 1;
                }
            }
            for (int i = 0; i < size; i++) {
                System.out.print(start + 1 + i + " ");
            }
            System.out.println();
            System.out.println(cur + 1);
        }
    }
}