杨辉三角形Java代码实现

 

使用二维数组打印一个 10 行杨辉三角：

1
1 1
1 2 1
1 3 3  1
1 4 6  4  1
1 5 10 10 5 1

package com.ietree.javabasic.array;

/**
 *  1
 *  1 1
 *  1 2 1
 *  1 3 3  1
 *  1 4 6  4  1
 *  1 5 10 10 5 1
 * 
 * 关键算法：arr[i][j] = arr[i-1][j]+arr[i-1][j-1]
 * 
 * @author hspcadmin
 */
public class PascalTriangle {

    public static void main(String[] args) {
        int[][] arr = new int[10][10];
        for (int i = 0; i < arr.length; i++) {
            for (int j = 0; j < i + 1; j++) {
                if (j == 0 || j == arr.length - 1) {
                    arr[i][j] = 1;
                } else {
                    arr[i][j] = arr[i - 1][j] + arr[i - 1][j - 1];
                }
                System.out.print(arr[i][j] + " ");
            }
            System.out.print("\n");
        }
    }

}