C 2024 day 19 part 1

c/2024/19/linen_layout.c

@@ -0,0 +1,49 @@
+#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);
+}