杨辉三角Java实现

import java.util.Scanner;

public class DemoTriangle {

    private int[][] store = null; // two ways array to store the values

    private int n = 0; //level

    public static void main(String[] args) {

        DemoTriangle demo = new DemoTriangle();

        //require a input integer to show how many level of Triangle

        demo.setN(demo.requriedInputValue());

        demo.calculateSet(demo.getN());

        demo.showTriangle(demo.getStore());

    }

    private void showTriangle(int[][] store) {

        //System.out.println("<----------->Result<----------->");

        int tempLength = store.length;

        for (int i = 0; i < store.length; i++) {

            System.out.print("levels " + (i + 1) + " :\t");

                for (int j = 0; j < tempLength - 1; j++) {

                    System.out.print("\t");

                }

                tempLength = tempLength - 1;

                for (int k = 0; k < store[i].length; k++) {

                    System.out.print(store[i][k] + "\t\t");

                }

                System.out.println();

        }

    }

    private int[][] calculateSet(int n) {

        store = new int[n + 1][];

        //create the two ways array

        for (int i = n; i >= 0; i--) {

            store[i] = new int[i+1];

        }

        //assign the values to the array

        for (int i = n; i >= 0; i--) {

            for (int j = 0; j <= i; j++) {

                int temp = this.calculateHierachy(i) / (this.calculateHierachy(j) * this.calculateHierachy(i -         j));

                store[i ][j] = temp;

            }

         }

        return store;

    }

    private int calculateHierachy(int n) {

        int temp = 1;

        if (n == 1 || n == 0) {

            return temp;

        } else {

            temp = n * calculateHierachy(n - 1);

            return temp;

        }

    }

    private int requriedInputValue() {

        System.out.println("Please input a number standing for level:");

        Scanner scaner = new Scanner(System.in);

        int n = scaner.nextInt();

        return n;

    }

    public int[][] getStore() {

        return store;

    }

    public void setStore(int[][] store) {

        this.store = store;

    }

    public int getN() {

        return n;

    }

    public void setN(int n) {

        this.n = n;

    }

}