117 lines
2.0 KiB
C++
117 lines
2.0 KiB
C++
#include <ctype.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
#define MAX(a, b) ((a) < (b)) ? (b) : (a)
|
|
|
|
int parse_int_and_advance(const char*& ptr)
|
|
{
|
|
int result = 0;
|
|
while (isdigit(*ptr))
|
|
result = (result * 10) + (*ptr++ - '0');
|
|
return result;
|
|
}
|
|
|
|
int puzzle1(FILE* fp)
|
|
{
|
|
int result = 0;
|
|
|
|
char buffer[256];
|
|
while (fgets(buffer, sizeof(buffer), fp))
|
|
{
|
|
const char* ptr = buffer;
|
|
|
|
if (strncmp("Game ", ptr, 5))
|
|
continue;
|
|
ptr += 5;
|
|
|
|
int id = parse_int_and_advance(ptr);
|
|
ptr += 2;
|
|
|
|
bool valid = true;
|
|
while (*ptr && valid)
|
|
{
|
|
int count = parse_int_and_advance(ptr);
|
|
|
|
ptr++;
|
|
if (strncmp(ptr, "red", 3) == 0)
|
|
valid = (count <= 12);
|
|
if (strncmp(ptr, "green", 5) == 0)
|
|
valid = (count <= 13);
|
|
if (strncmp(ptr, "blue", 4) == 0)
|
|
valid = (count <= 14);
|
|
|
|
while (*ptr && !isdigit(*ptr))
|
|
ptr++;
|
|
}
|
|
|
|
if (valid)
|
|
result += id;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
int puzzle2(FILE* fp)
|
|
{ int result = 0;
|
|
|
|
char buffer[256];
|
|
while (fgets(buffer, sizeof(buffer), fp))
|
|
{
|
|
const char* ptr = buffer;
|
|
|
|
if (strncmp("Game ", ptr, 5))
|
|
continue;
|
|
ptr += 5;
|
|
|
|
int id = parse_int_and_advance(ptr);
|
|
ptr += 2;
|
|
|
|
int needed_red = 0;
|
|
int needed_green = 0;
|
|
int needed_blue = 0;
|
|
|
|
while (*ptr)
|
|
{
|
|
int count = parse_int_and_advance(ptr);
|
|
|
|
ptr++;
|
|
if (strncmp(ptr, "red", 3) == 0)
|
|
needed_red = MAX(needed_red, count);
|
|
if (strncmp(ptr, "green", 5) == 0)
|
|
needed_green = MAX(needed_green, count);
|
|
if (strncmp(ptr, "blue", 4) == 0)
|
|
needed_blue = MAX(needed_blue, count);
|
|
|
|
while (*ptr && !isdigit(*ptr))
|
|
ptr++;
|
|
}
|
|
|
|
result += needed_red * needed_green * needed_blue;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
int main(int argc, char** argv)
|
|
{
|
|
const char* file_path = "/usr/share/aoc2023/day2_input.txt";
|
|
if (argc >= 2)
|
|
file_path = argv[1];
|
|
|
|
FILE* fp = fopen(file_path, "r");
|
|
if (fp == nullptr)
|
|
{
|
|
perror("fopen");
|
|
return 1;
|
|
}
|
|
|
|
printf("puzzle1: %d\n", puzzle1(fp));
|
|
|
|
fseek(fp, 0, SEEK_SET);
|
|
|
|
printf("puzzle2: %d\n", puzzle2(fp));
|
|
|
|
fclose(fp);
|
|
}
|