The even decomposition

Goldbach conjecture: any even number greater than six can be split into two prime numbers and print out all the possible
inputs for all boundary even number n, n may be output
as input
100
Output:
100 = 3 + 97
100 + 11 = 89
100 = +83 17
100 = 29 + 71
100 = +59 41
100 = 47 + 53

 

package chapter04;

import java.util.Scanner;

public class test01 {
	//将偶数拆分成俩质数的和
	public static void main(String[] args) {
		int num=inPut();
		outPut(num);
		
	}
	
	public static int inPut(){
		//输入数字并通过检验确定一个符合要求的数
		Scanner sc=new Scanner(System.in);
		int num=sc.nextInt();
		if(num%2!=0||num<=6){
			System.out.println("输入错误，请重新输入大于6的偶数：");
			return inPut();//错误则返回inPut()继续输入
		}
		return num;//正确则返回num值
	}
	
	public static boolean isPrim(int num){
		//判断是否是质数
		for(int i=2;i<=Math.sqrt((double)num);i++){
			if(num%i==0){
				return false;
			}
		}
		return true;
	}
	
	public static void outPut(int num){
		//输出所有符合条件的质数对
		for(int i=2;i<=num/2;i++){
			if(isPrim(i)==true&&isPrim(num-i)==true){	
				System.out.println(num+"="+i+"+"+(num-i));
			}
		}
	}
 
 
}