aoc_omni/c/2022/3/rucksack_reorganization.c

106 lines
2.1 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "../../lib/aoc.h"
typedef struct Compartment {
char contents[52];
} Compartment;
void print_compartment(Compartment *c) {
for (char i = 'a'; i <= 'z'; i++) {
printf("%c", i);
}
for (char i = 'A'; i <= 'Z'; i++) {
printf("%c", i);
}
printf("\n");
for (char i = 0; i < 52; i++) {
printf("%d", c->contents[i]);
}
printf("\n\n");
}
Compartment fill_compartment(const char *half) {
Compartment compartment;
for (char i = 0; i < 52; i++) {
compartment.contents[i] = 0;
}
for (int i = 0; i < strlen(half); i++) {
char c = half[i];
if (c >= 'a' && c <= 'z') {
compartment.contents[c - 'a'] = 1;
} else {
compartment.contents[c - 'A' + 26] = 1;
}
}
fflush(stdout);
return compartment;
}
int priority(char *line) {
int len = strlen(line);
char *second = malloc((len / 2) + 1);
strcpy(second, line + (len / 2));
line[len / 2] = '\0';
Compartment c1 = fill_compartment(line);
Compartment c2 = fill_compartment(second);
// print_compartment(&c1);
// print_compartment(&c2);
for (int i = 0; i < 52; i++) {
if (c1.contents[i] && c2.contents[i]) {
free(second);
return i + 1;
}
}
free(second);
return 0;
}
int three_line_priority(char *one, char *two, char *three) {
Compartment c1 = fill_compartment(one);
Compartment c2 = fill_compartment(two);
Compartment c3 = fill_compartment(three);
for (int i = 0; i < 52; i++) {
if (c1.contents[i] && c2.contents[i] && c3.contents[i]) {
return i + 1;
}
}
return 0;
}
int main() {
char *line;
int sum = 0;
while ((line = aoc_read_line()) != NULL) {
sum += priority(line);
}
aoc_reset_read_line();
int three_line_sum = 0;
char *line_1, *line_2, *line_3;
while (
(line_1 = aoc_read_line()) != NULL &&
(line_2 = aoc_read_line()) != NULL &&
(line_3 = aoc_read_line()) != NULL
) {
three_line_sum += three_line_priority(line_1, line_2, line_3);
}
printf("Part 1: %d\n", sum);
printf("Part 2: %d\n", three_line_sum);
aoc_free();
return 0;
}