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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <math.h>
 
struct row
{
	unsigned long n[12];
	unsigned long target;
	int len;
};
 
static unsigned long sum(struct row *r, unsigned int mask)
{
	unsigned long tot = 0;
	int i;
 
	tot = r->n[0];
 
	for(i = 1; i < r->len; i++)
	{
		if(mask & 1)
			tot *= r->n[i];
		else
			tot += r->n[i];
		mask >>= 1;
	}
 
	return tot;
}
 
static int dop1(struct row *r)
{
	unsigned int mask;
	unsigned int siz;
 
	siz = (1 << r->len)-1;
 
	for(mask = 0; mask < siz; mask++)
	{
		if(sum(r, mask) == r->target)
			return 1;
	}
 
	return 0;
}
 
static int p2_mul(struct row *r, int depth, unsigned long sum);
static int p2_or(struct row *r, int depth, unsigned long sum);
 
static int p2_add(struct row *r, int depth, unsigned long sum)
{
	if(depth >= r->len)
		return 0;
 
	sum += r->n[depth];
	if(sum == r->target && depth == r->len-1)
		return 1;
 
	if(sum > r->target)
		return 0;
 
 
	if(p2_add(r, depth+1, sum))
		return 1;
	if(p2_or(r, depth+1, sum))
		return 1;
	if(p2_mul(r, depth+1, sum))
		return 1;
 
	return 0;
}
 
static int p2_or(struct row *r, int depth, unsigned long sum)
{
	if(depth >= r->len)
		return 0;
 
	if(r->n[depth] < 10)
		sum = sum * 10 + r->n[depth];
	else if(r->n[depth] < 100)
		sum = sum * 100 + r->n[depth];
	else
		sum = sum * 1000 + r->n[depth];
 
	if(sum == r->target && depth == r->len-1)
		return 1;
 
	if(sum > r->target)
		return 0;
 
 
	if(p2_add(r, depth+1, sum))
		return 1;
	if(p2_or(r, depth+1, sum))
		return 1;
	if(p2_mul(r, depth+1, sum))
		return 1;
 
	return 0;
}
 
static int p2_mul(struct row *r, int depth, unsigned long sum)
{
	if(depth >= r->len)
		return 0;
 
	sum *= r->n[depth];
	if(sum == r->target && depth == r->len-1)
		return 1;
 
	if(sum > r->target)
		return 0;
 
	if(p2_add(r, depth+1, sum))
		return 1;
	if(p2_or(r, depth+1, sum))
		return 1;
	if(p2_mul(r, depth+1, sum))
		return 1;
 
	return 0;
}
 
static int dop2a(struct row *r)
{
	unsigned long sum = 0;
 
	sum = r->n[0];
 
	if(p2_add(r, 1, sum))
		return 1;
	if(p2_or(r, 1, sum))
		return 1;
	if(p2_mul(r, 1, sum))
		return 1;
 
	return 0;
}
 
static unsigned long sum2(struct row *r, unsigned int mask)
{
	unsigned long tot = 0;
	int i;
 
	tot = r->n[0];
 
	for(i = 1; i < r->len; i++)
	{
		if(mask % 3 == 0)
			tot *= r->n[i];
		else if(mask % 3 == 1)
			tot += r->n[i];
		else
		{
			if(r->n[i] < 10)
				tot = tot*10 + r->n[i];
			else if(r->n[i] < 100)
				tot = tot*100 + r->n[i];
			else
				tot = tot*1000 + r->n[i];
		}
		if(tot > r->target)
			return 0;
		mask /= 3;
	}
 
	return tot;
}
 
static int dop2(struct row *r)
{
	unsigned int siz, mask;
 
	siz = powl(3, r->len-1);
 
	for(mask = 0; mask < siz; mask++)
	{
		if(sum2(r, mask) == r->target)
			return 1;
	}
 
	return 0;
}
 
static void timedump(struct timeval *t1, struct timeval *t2)
{
	unsigned long sec  = t2->tv_sec - t1->tv_sec;
	unsigned long usec = t2->tv_usec - t1->tv_usec;
 
	if(sec)
	{
		printf("%lu.%lus", sec, usec/1000);
		return;
	}
 
	if(usec > 1000)
	{
		printf("%lums", usec/1000);
		return;
	}
 
	printf("%luµs", usec);
}
 
int main(void)
{
	FILE *f;
	struct timeval t1, t2;
	unsigned long long p1 = 0, p2 = 0;
 
	f = fopen("day7.txt", "rb");
	if(!f)
		return 1;
 
	gettimeofday(&t1, NULL);
 
	while(1)
	{
		char buf[1024];
		struct row r = {0};
		char *p = buf;
		int i;
 
		if(!fgets(buf, 1024, f))
			break;
 
		if(buf[0] == '\n')
			break;
 
		r.target = strtol(buf, &p, 10);
 
		p++;
		i = 0;
 
		while(1)
		{
			r.n[i] = strtol(p, &p, 10);
			i++;
 
			if(*p == ' ')
				p++;
			if(!*p || *p == '\n')
				break;
		}
 
		r.len = i;
 
		if(dop1(&r))
			p1 += r.target;
		if(dop2a(&r))
			p2 += r.target;
	}
 
	gettimeofday(&t2, NULL);
	printf("p1: %llu, p2: %llu in ", p1, p2);
	timedump(&t1, &t2);
	putchar('\n');
 
	return 0;
}