Java模拟法解决回型矩阵

Java模拟

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int cnt = 1;
        int l = 0, r = n - 1;
        int u = 0, d = n - 1;
        int[][] a = new int[n][n];
        while (cnt <= n * n) {
            for (int j = l; j <= r; j++) {// 左到右
                a[u][j] = cnt++;
            }
            u++;// 往下移动一行
            for (int i = u; i <= d; i++) {// 上到下
                a[i][r] = cnt++;
            }
            r--;// 往左移动一列
            for (int j = r; j >= l; j--) {// 右到左
                a[d][j] = cnt++;
            }
            d--;// 往上移动一行
            for (int i = d; i >= u; i--) {// 下到上
                a[i][l] = cnt++;
            }
            l++;// 往右移动一列
        }
        for (int i = 0; i < a.length; i++) {
            for (int j = 0; j < a.length; j++) {
                System.out.print(a[i][j] + " ");
            }
            System.out.println();
        }
    }
}