# Java 程序：打印 Pascal 三角形

> 原文： [https://beginnersbook.com/2019/02/java-program-to-print-pascal-triangle/](https://beginnersbook.com/2019/02/java-program-to-print-pascal-triangle/)

在本教程中，我们将编写一个 java 程序来打印 [Pascal 三角](https://en.wikipedia.org/wiki/Pascal's_triangle) 。

## 示例：打印 Pascal 三角

在此程序中，要求用户输入行数，并根据输入，使用输入的行数打印 pascal 三角形。

```java
package com.beginnersbook;
import java.util.Scanner;
public class JavaExample {
    static int fact(int num) {
	int factorial;

	for(factorial = 1; num > 1; num--){
		factorial *= num;
	}
	return factorial;
    }
    static int ncr(int n,int r) {
	return fact(n) / ( fact(n-r) * fact(r) );
    }
    public static void main(String args[]){
	int rows, i, j;

	//getting number of rows from user
	System.out.println("Enter number of rows:");
	Scanner scanner = new Scanner(System.in);
	rows = scanner.nextInt();
	scanner.close();

	System.out.println("Pascal Triangle:");
	for(i = 0; i < rows; i++) {
		for(j = 0; j < rows-i; j++){
			System.out.print(" ");
		}
		for(j = 0; j <= i; j++){
			System.out.print(" "+ncr(i, j));
		}
		System.out.println();
 	}
    }
}

```

**输出：**

![Java Program to print Pascal Triangle](img/97fa18fac4a80ab2d2a8a36905256cb7.jpg)

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