Java 实现简单的上三角

import java.util.Scanner;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int N = sc.nextInt();
        int count = 1;
        int[][] a = new int [N][N];
        for(int i = 0 ;i<=a.length/2-1;i++) {
            for(int j =i;j<=a.length-i-1-i;j++) {
                a[i][j] = count++;
            }
            for(int k = i+1;k<=a.length-i-1-i;k++) {
                a[k][N-i-k-1] = count++;
            }
            for(int j = a.length-i-2;j>=2*i+1;j--) {
                a[j-i][i] = count++;
            }
        }
        for(int i = 0 ; i <a.length;i++) {
            for(int j = 0;j<a[i].length;j++) {
                if(a[i][j]==0){
                    continue;
                }
                System.out.printf("%4d",a[i][j]);
            }
            System.out.println();
        }

    }
}