代码实现:打印出杨辉三角形

//打印出杨辉三角形
public class Test {

	public static void main(String[] args) {
		int[][] n = new int[10][21];
		n[0][10] = 1;
		for (int i = 1; i < 10; i++)
			for (int j = 10 - i; j < 10 + i + 1; j++)
				n[i][j] = n[i - 1][j - 1] + n[i - 1][j + 1];
		for (int i = 0; i < 10; i++) {
			for (int j = 0; j < 21; j++) {
				if (n[i][j] == 0)
					System.out.print("   ");
				else {
					if (n[i][j] < 10)
						System.out.print("  " + n[i][j]);// 空格为了美观需要
					else if (n[i][j] < 100)
						System.out.print(" " + n[i][j]);
					else
						System.out.print(n[i][j]);
				}
			}
			System.out.println();
		}
	}
}