View Code of Problem 91

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class exercise {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		List<Integer> list = new ArrayList<>();
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		dfs(n,list);
		System.out.print(n+"=");
		for(int i=0;i<list.size();i++) 
		{
			if(i==list.size()-1)
				System.out.print(list.get(i));
			else
				System.out.print(list.get(i)+"*");
		}
	}
	static void dfs(int n,List<Integer> list) 
	{
		if(n==1) return;
		for(int i=2;i<=n;i++) 
		{
			if(isPrime(i)) 
			{
				if(n%i==0) 
				{
					list.add(i);
					dfs(n/i,list);
					break;
				}
			}
		}
		
	}
	static boolean isPrime(int n) 
	{
		if(n==1) return false;
		for(int i=2;i<=Math.sqrt(n);i++) 
		{
			if(n%i==0) return false;
		}
		return true;
	}
}
/*
Main.java:6: error: class exercise is public, should be declared in a file named exercise.java
public class exercise {
       ^
1 error
*/