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 sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int num = sc.nextInt();
            String action = sc.next();
            musicUpDown(num, action);
        }
    }

    private static void musicUpDown(int num, String action) {
        char[] acValue = action.toCharArray();
        int top = 1;
        int cur = 1;
        for (char c : acValue) {
            if (c == 'U') {
                if (cur == 1) {
                    cur = num;
                    top = num > 4 ? cur - 3 : 1;
                } else {
                    //当前光标和当页首行相等时向上滚动
                    if (top == cur) {
                        top--;
                    }
                    cur--;
                }
            } else {
                if (cur == num) {
                    cur = 1;
                    top = 1;
                } else {
                    //当前光标和当页尾行相等时向下滚动
                    if (cur == top + 3) {
                        top++;
                    }
                    cur++;
                }
            }
        }
        int res = Math.min(num, top + 3);
        for (int i = top; i <= res; i++) {
            if (i != top) {
                System.out.print(" ");
            }
            System.out.print(i);
        }
        System.out.println("\n" + cur);
    }
}