一半的 杨辉三角

 

 输出这样的

配合代码好好解析

 

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int arr[][] = new int[n][n];
        for (int i = 0; i < n; i++) {
            arr[i][0] = 1;
            arr[i][i] = arr[i][0];
        }
        for (int i = 2; i < n; i++) {
            for (int j = 1; j < i; j++) {
                arr[i][j] = (arr[i - 1][j] + arr[i - 1][j - 1]);
            }
        }

        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < arr[i].length; j++) {
                if(arr[i][j] != 0) {
                    if (j == arr[i].length - 1) {
                        System.out.print(arr[i][j]);
                    } else {
                        System.out.print(arr[i][j] + " ");
                    }
                }

            }
            System.out.println();

        }
    }
}