#include "header.h"

//check if x is a prime
int primetest(int x, int arraybound, int *array)
{
//x is the prime being checked.
//arraybound is the first UNFILLED entry in the array.
//array holds the primes we've found so far.
int test=0,check=1;
//test is the current index of the array we are comparing against.
//check is what I used instead of breaking from the while when primality fails
//check is set to 1; if x is composite, it's set to the first prime factor.
int upperlimit=(int) ceil(sqrt(x));
//upperlimit is the rounded up square root of the 
while (test<arraybound && array[test] <= upperlimit && check==1)
//If the prime were dividing with is inside the array, AND
//If the prime were dividing with is less then or equal to the upper limit AND
//If the number hasn't shown it's got a prime factor yet
//THEN try these next steps.
{
	if (x%array[test] == 0)
	{
		check=array[test];
	}
	test++;
}
return check;
//Return the least prime factor, or 1 if it's prime.
}

//loop through all the values until we have filled out primal requirements
int loopthrough(int n,int* array)
{
int i=0;	//This is the current index of the array being filled.
int curr=1;	//This is the current number being tested for primeness.
		//It's incrimented before we start, so 1 is ignored.
//int i=1 ,curr=2;
//array[0]=2;	//The primetest behavior is undefined if the array is empty.
		//Or not. The primetest triggers properly for input "2".
while (i < n)
{
	curr++;	//The first time through, curr becomes two!  All is safe.
	if (primetest(curr,i,array)==1)
	{
		//Found one!  INTO THE ARRAY WITH YOU!  HAR HAR HAR!
		array[i]=curr;
		i++;
	}
}
return i;
}