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part 1 working, part 2 brute force up to max int, solution may be over max int

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tomoron
2024-12-17 17:53:21 +01:00
parent cd4ef3ff9d
commit cb4b212ab4
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/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* part2.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: tomoron <tomoron@student.42.fr> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2024/07/17 23:03:36 by tomoron #+# #+# */
/* Updated: 2024/12/17 17:50:43 by tomoron ### ########.fr */
/* */
/* ************************************************************************** */
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <math.h>
#include <string.h>
#include <sys/time.h>
#include "libft/libft.h"
static long int get_register(char *str)
{
while(*str && *str != ':')
str++;
return(ft_atoi(str + 1));
}
static void parse_input(char **split, int *reg, uint8_t **ops, size_t *len)
{
char *tmp;
int i;
reg[0] = get_register(*split);
split++;
reg[1] = get_register(*split);
split++;
reg[2] = get_register(*split);
split++;
*len = 0;
tmp = *split;
while(*tmp)
{
if(ft_isdigit(*tmp))
(*len)++;
tmp++;
}
i = 0;
*ops = malloc(*len);
tmp = *split;
while(*tmp)
{
while(*tmp && !ft_isdigit(*tmp))
tmp++;
if(*tmp)
(*ops)[i] = (uint8_t)atoi(tmp);
i++;
while(ft_isdigit(*tmp))
tmp++;
}
}
static int combo(uint8_t val, int *reg)
{
if(val <= 3)
return(val);
if(val == 7)
{
printf("err\n");
exit(1);
}
return(*(reg + (val - 4)));
}
static size_t exec_instructions(uint8_t *ops, int *reg, size_t len, uint8_t *out)
{
size_t instr_ptr;
size_t out_ptr;
instr_ptr = 0;
out_ptr = 0;
while(instr_ptr < len)
{
// printf("op : %d, %d\n", ops[instr_ptr], ops[instr_ptr + 1]);
switch (ops[instr_ptr])
{
case 0:
reg[0] = reg[0] / pow(2, combo(ops[instr_ptr + 1], reg));
instr_ptr += 2;
break;
case 1:
reg[1] = reg[1] ^ ops[instr_ptr + 1];
instr_ptr += 2;
break;
case 2:
reg[1] = combo(ops[instr_ptr + 1], reg) % 8;
instr_ptr += 2;
break;
case 3:
if(reg[0])
instr_ptr = ops[instr_ptr + 1];
else
instr_ptr += 2;
break;
case 4:
reg[1] = reg[1] ^ reg[2];
instr_ptr += 2;
break;
case 5:
out[out_ptr++] = combo(ops[instr_ptr + 1], reg) % 8;
instr_ptr += 2;
break;
case 6:
reg[1] = reg[0] / pow(2, combo(ops[instr_ptr + 1], reg));
instr_ptr += 2;
break;
case 7:
reg[2] = reg[0] / pow(2, combo(ops[instr_ptr + 1], reg));
instr_ptr += 2;
break;
}
if(out_ptr == len)
break;
}
return(out_ptr);
}
void show_progress(struct timeval start, int cur)
{
struct timeval now;
double itps;
double sec_diff;
gettimeofday(&now, 0);
sec_diff = (((double)now.tv_usec - (double)start.tv_usec) / 1000000) + (now.tv_sec - start.tv_sec);
itps = cur / sec_diff;
printf("currently: %d, itps : %f, time remaining until max int : %fs \r", cur, itps, (2147483647 - cur) / itps);
fflush(stdout);
}
long int resolve_part2(char *input, char **split)
{
(void)input;
int reg[3];
uint8_t *ops;
size_t len;
uint8_t *out;
size_t out_len;
int i;
struct timeval start;
parse_input(split, reg, &ops, &len);
out = malloc(len);
gettimeofday(&start, 0);
i = 1;
while(1)
{
reg[0] = i;
reg[1] = 0;
reg[2] = 0;
out_len = exec_instructions(ops, reg, len, out);
if(out_len == len && !memcmp(out, ops, len))
return(i);
i++;
if(i % 1000000 == 0)
show_progress(start, i);
}
return(0);
}