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.hasNext()) { // 注意 while 处理多个 case
            String n = in.nextLine();
            int num = Integer.parseInt(n);
            String str = in.nextLine();
            int top = 1; //当前光标指向哪
            int[] arr = new int[5]; //当前页面那四个都是啥

            if (num <= 4) {
                for (int i = 1; i <= num; i++) {
                    arr[i] = i;
                }
                for (int i = 0; i < str.length(); i++) {
                    if (str.charAt(i) == 'U') {
                        if (top == 1) {
                            top = num;
                        } else if (top > 1) {
                            top--;
                        }
                    } else if (str.charAt(i) == 'D') {
                        if (top == num) {
                            top = 1;
                        } else if (top < num) {
                            top++;
                        }
                    }
                }
                for (int i = 1; i <= num; i++) {
                    System.out.print(arr[i] + " ");
                }
                System.out.println();
                System.out.println(arr[top]);
            } else {
                for (int i = 1; i <= 4; i++) {
                    arr[i] = i;
                }
                for (int i = 0; i < str.length(); i++) {
                    if (str.charAt(i) == 'U') {
                        if (top == 1) {
                            if (arr[1] == 1) {
                                arr[1] = num - 3;
                                arr[2] = num - 2;
                                arr[3] = num - 1;
                                arr[4] = num;
                                top = 4;
                            } else {
                                for (int j = 1; j <= 4; j++) {
                                    arr[j] = arr[j] - 1;
                                }
                            }
                        } else {
                            top--;
                        }
                    } else if (str.charAt(i) == 'D') {
                        if (top == 4) {
                            if (arr[4] == num) {
                                arr[1] = 1;
                                arr[2] = 2;
                                arr[3] = 3;
                                arr[4] = 4;
                                top = 1;
                            } else {
                                for (int j = 1; j <= 4; j++) {
                                    arr[j] = arr[j] + 1;
                                }
                            }
                        } else {
                            top++;
                        }
                    }
                }
                for (int i = 1; i <= 4; i++) {
                    System.out.print(arr[i] + " ");
                }
                System.out.println();
                System.out.println(arr[top]);
            }

        }
    }
}