代码
package day3;public class Demo2 {public static void main(String[] args) {// TODO Auto-generated method stub// for (int i = 0; i < 10; i++) {// for (int j = 0; j < 10; j++) {// System.out.print("外："+i+"内："+j);// }// System.out.println();// }int n = 6; int [][] arr = new int [n+1][n+1];for (int i = 1; i < arr.length; i++) {for (int j = 1; j <=i; j++) {if(i==1||i==j) {arr[i][j]=1;}else {arr[i][j]=arr[i-1][j]+arr[i-1][j-1];}}}for (int i = 1; i < arr.length; i++) {for (int j = 1; j <=i; j++) {System.out.print(arr[i][j]+",");}System.out.println();} }
}
i内层，j外层
核心：每个位置的值为(i-1,j)位置的值加(i-1,j-1)位置的值
运行结果
