#include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdbool.h> #include "../../lib/aoc.h" typedef char Towel[10]; typedef struct Towels { Towel towels[2000]; int towels_count; } Towels; bool towels_valid_design(Towels *t, char *design) { if (strlen(design) == 0) return true; for (int i = 0; i < t->towels_count; i++) { if (strstr(design, t->towels[i]) == design) { if (towels_valid_design(t, design + strlen(t->towels[i]))) return true; } } return false; } int main() { char *line; Towels towels; towels.towels_count = 0; line = aoc_read_line(); char *token = strtok(line, ", "); while (token != NULL) { strcpy(towels.towels[towels.towels_count++], token); token = strtok(NULL, ", "); } aoc_read_line(); // blank line int valid_designs = 0; while ((line = aoc_read_line()) != NULL) { if (towels_valid_design(&towels, line)) valid_designs++; } printf("Part 1: %d\n", valid_designs); aoc_free(); exit(0); }