Game improvement of smart people: Lesson 2 of Chapter 3: number of factors

#include <iostream>
#include <cstdio>
using namespace std;
int k,i,s,t,j;
int f(int a)
{
	s=0;
	for (j=1;j*j<=a;j++)
	{
		if (a%j==0)
			s+=2;
	}
	j--;
	if (j*j==a)
		s--;
	return s;
}
int main()
{
	cin >>k;
	for (i=1;i<=20000;i++)
	{
		if (f(i)==k)
		{
			t=i;
			cout <<i <<endl;
			break;
		}
	}
	if (t==0)
		cout <<"NO SOLUTION";
	else
	{
		for (i=1;i<=t/2;i++)
			if (t%i==0)
				cout <<i <<" ";
		cout <<t;
	}
	return 0; 
}