달팽이 순회2

import java.util.Scanner;

public class Main {
    public static final int MAX_VAL = 100;
    // 동 남 서 북
    public static int[] dx = new int[]{0, 1, 0, -1};
    public static int[] dy = new int[]{1, 0, -1, 0};
    public static char[][] arr = new char[MAX_VAL][MAX_VAL];

    public static int moveDirection = 0;

    public static boolean inRange(int x, int y, int n, int m) {
        return (0 <= x && x < n && 0 <= y && y < m) && (arr[x][y] == 0);
    }

    // 시계 방향으로 return
    public static void changeDir() {
        moveDirection = (moveDirection + 1) % 4;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        char a = 'A';
        int x = 0;
        int y = 0;

        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                while (true) {
                    int nx = x + dx[moveDirection];
                    int ny = y + dy[moveDirection];

                    if (i == n - 1 && j == m - 1) {
                        arr[x][y] = a;
                        break;
                    }
                    // inRange안에 들어가지 않는다면
                    if (!inRange(nx, ny, n, m)) {
                        changeDir();
                    } else {
                        arr[x][y] = a;
                        if ( a >= 'Z') {
                            a = 'A';
                        } else {
                            a++;
                        }
                        x = nx;
                        y = ny;
                        break;
                    }
                }
            }
        }

        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (arr[i][j] != 0) {
                    System.out.print(arr[i][j] + " ");
                }

            }
            System.out.println();
        }

    }
}

 

알고리즘 너무 재미있당 ㅎㅅㅎ