Java——因式分解算法

package com.zth1;
/**
 * 因式分解
 * @author 时光·漫步
 */

import java.util.Scanner;

public class YinShi{
  
  private static int fun(int num) {
    
    if(num<1) {
      System.out.println("输入有误");
      return 0;
    }
    if(num == 1) {
      System.out.print(1);
      return 0;
    }
    for(int i= 2;i<= Math.sqrt(num);i++) {
      while(num%i ==0) {
        System.out.print(i+" ");
        num /=i;
      }
    }
    if(num >1) {
      System.out.println(num);
    }
    return 0;
  }
  
  public static void  main(String args[]) {
    
    Scanner scanner = new Scanner(System.in);
    System.out.print("请输入被分解的正整数：");
    int num = scanner.nextInt();
    scanner.close();
    fun(num);
  }
}