Help in c

int power(int x, int y) /* function that calculates a power number */
{
	int sum;
	for (sum=1; y>0; y--)
		sum*=x;
	return sum;
}
int lg(int base, int x) /*function that finds the power number */
{
	int counter=0, temp=1;
	while (x>temp)
	{
		temp=temp*base;
		counter++;
	}
		return counter;
}
void geometric()
{
	int i=0,j,q=2,n=0,a1=0,num,sum, temp;
	int solution[3][10000];
	for (j=0;j<10000; j++)
	{
		solution[0][j]=0;
		solution[1][j]=0;
		solution[2][j]=0;
	}
	/* first, get the num for the sum of the serie */
	num=get_int();
	/*now, find a1 and a sutiable q and n from a1=1, q=2*/
	for (q=2; q<num; q++)
			for (a1=1; a1<num; a1++)
			{
				temp=(int)(((num*(q-1))/a1)+1);
				n=lg(q,temp);
				sum=(int)((a1*(power(q,n)-1)/(q-1)));
				if (num==sum)
				{
					printf("G");
					solution[0][i]=n;        /* the output is this array */
					solution[1][i]=a1;       /*  which contains in each  */
					solution[2][i]=q;        /*  column n, a1 and q for  */ 
					i++;                     /*         the sum          */
				}
			}
	for (j=0; solution[0][j]!=0; j++)
		printf("a1=%d q=%d n=%d\n",solution[1][j],solution[2][j],solution[0][j]);
}