Unnamed

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>

void refresh();
int power(int a, int b);
int checkBlocks(int b);
void printBlocks();
int createBlocks();

int col[9], mat[3][9], tcol[9], row[9], block[9], fin, ci, ri, bi, r, i, pr, ud, d;

void refresh(int complete)
{
	for(fin=0;fin<9;fin++)
	{
		if (complete) col[fin]=0;
		tcol[fin]=0;
		row[fin]=0;
		block[fin]=0;
	}
	ci=0;
	ri=0;
	bi=0;
	fin=0;
}

int main(int argc, char *argv[])
{
	if (argc!=2)
	{
		printf("[difficulty (1-9)]\n");
		return 1;
	}
	ud = (*argv[1]-48);
	if (ud<1)
	{
		printf("error: invalid, setting to 1\n");
		ud = 1;
	}
	srand(time(NULL));
	while(createBlocks(col));
	while(createBlocks(col));
	while(createBlocks(col));
	return 0;
}

int power(int a, int b)
{
	int ret = 1, i=0;
	for(i=0;i<b;i++) ret = ret * a;
	return ret;
}

int checkBlocks(int b)
{
	int block[3];
	block[0]=power(2,(mat[b*3][0])-1)+power(2,(mat[b*3][1])-1)+power(2,(mat[b*3][2])-1) + power(2,(mat[(b*3)+1][0])-1)+power(2,(mat[(b*3)+1][1])-1)+power(2,(mat[(b*3)+1][2])-1) + power(2,(mat[(b*3)+2][0])-1)+power(2,(mat[(b*3)+2][1])-1)+power(2,(mat[(b*3)+2][2])-1);

	if ((block[0] & 511)!=511) return 1;

	block[1]=power(2,(mat[b*3][3])-1)+power(2,(mat[b*3][4])-1)+power(2,(mat[b*3][5])-1) + power(2,(mat[(b*3)+1][3])-1)+power(2,(mat[(b*3)+1][4])-1)+power(2,(mat[(b*3)+1][5])-1) + power(2,(mat[(b*3)+2][3])-1)+power(2,(mat[(b*3)+2][4])-1)+power(2,(mat[(b*3)+2][5])-1);

	if ((block[1] & 511)!=511) return 1;

	block[2]=power(2,(mat[b*3][6])-1)+power(2,(mat[b*3][7])-1)+power(2,(mat[b*3][8])-1) + power(2,(mat[(b*3)+1][6])-1)+power(2,(mat[(b*3)+1][7])-1)+power(2,(mat[(b*3)+1][8])-1) + power(2,(mat[(b*3)+2][6])-1)+power(2,(mat[(b*3)+2][7])-1)+power(2,(mat[(b*3)+2][8])-1);

	if ((block[2] & 511)!=511) return 1;
	else return 0;
}

void printBlocks()
{
	int aa, bb;
	for(aa=0;aa<3;aa++)
	{
		for(bb=0;bb<9;bb++)
		{
			if ((rand() % 10) < ud) printf("* ");
			else printf("%d ",mat[aa][bb]);
		}
		printf("\n");
	}
}

int createBlocks(int col[9])
{
	refresh(0);
	while(fin++<3)
	{
		while(row[ri]<511)
		{
			r = (rand() % 9) + 1;
			pr = power(2,r-1);
			if (((pr & (tcol[ci] | col[ci]))==0) && (((pr & row[ri]))==0))
			{
				row[ri] = row[ri] + pr;
				mat[ri][ci]=r;
				tcol[ci] = tcol[ci] + pr;
				ci++;
			} else if ((row[ri] | (tcol[ci] | col[ci]))==511) return 1;
		}
		if (ri==2)
		{
			if (checkBlocks(0)) return 1;
			else
			{
				for(i=0;i<9;i++) col[i]=(tcol[i] | col[i]);
				printBlocks();
				return 0;
			} 
		}
		ci=0;
		ri++;
	}
	return 0;
}