c 2024 Penultimate day part 1

c/2024/24/crossed_wires.c

@@ -0,0 +1,127 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+
+#include "../../lib/aoc.h"
+
+typedef struct WireValue {
+  char name[4];
+  char l[4];
+  char op[4];
+  char r[4];
+  bool value;
+  bool resolved;
+} WireValue;
+
+typedef struct Grove {
+  WireValue wires[400];
+  int wires_count;
+} Grove;
+
+WireValue *grove_wire_by_name(Grove *g, const char *name) {
+  for (int i = 0; i < g->wires_count; i++) {
+    if (strcmp(name, g->wires[i].name) == 0) return &(g->wires[i]);
+  }
+  return NULL;
+}
+
+bool grove_more_to_resolve(Grove *g) {
+  for (int i = 0; i < g->wires_count; i++) {
+    if (g->wires[i].resolved == false) return true;
+  }
+  
+  return false;
+}
+
+void grove_resolve(Grove *g) {
+  for (int i = 0; i < g->wires_count; i++) {
+    if (g->wires[i].resolved) continue;
+
+    WireValue *l, *r;
+    l = grove_wire_by_name(g, g->wires[i].l);
+    r = grove_wire_by_name(g, g->wires[i].r);
+    if (l == NULL || r == NULL) printf("ERROR: BAD WIRE I GUESS\n");
+    if (l->resolved && r->resolved) {
+      switch (g->wires[i].op[0]) {
+      case 'A':
+	g->wires[i].value = l->value && r->value;
+	break;
+      case 'O':
+	g->wires[i].value = l->value || r->value;
+	break;
+      case 'X':
+	g->wires[i].value = (l->value + r->value) % 2;
+	break;
+      }
+      g->wires[i].resolved = true;
+    }
+  }
+}
+
+int main() {
+  Grove g;
+
+  char *line, *token;
+  char l[4], op[4], r[4], name[4];
+  int value;
+
+  bool done_with_init = false;
+  while ((line = aoc_read_line()) != NULL) {
+    if (strcmp(line, "") == 0) {
+      done_with_init = true;
+      continue;
+    }
+
+    if (done_with_init) {
+      token = strtok(line, " ");
+      strcpy(g.wires[g.wires_count].l, token);
+      token = strtok(NULL, " ");
+      strcpy(g.wires[g.wires_count].op, token);
+      token = strtok(NULL, " -> ");
+      strcpy(g.wires[g.wires_count].r, token);
+      token = strtok(NULL, " -> ");
+      strcpy(g.wires[g.wires_count].name, token);
+      g.wires[g.wires_count].resolved = false;
+      g.wires_count++;
+    } else {
+      sscanf(line, "%c%c%c: %d", &(name[0]), &(name[1]), &(name[2]), &value);
+      name[3] = '\0';
+      strcpy(g.wires[g.wires_count].name, name);
+      g.wires[g.wires_count].value = value;
+      g.wires[g.wires_count].resolved = true;
+      g.wires_count++;
+    }
+  }
+
+  while (grove_more_to_resolve(&g)) {
+    grove_resolve(&g);
+  }
+
+  char z[100], guy[3];
+  guy[2] = '\0';
+  int z_index;
+  int max_z_index = 0;
+
+  for (int i = 0; i < g.wires_count; i++) {
+    if (g.wires[i].name[0] != 'z') continue;
+    guy[0] = g.wires[i].name[1];
+    guy[1] = g.wires[i].name[2];
+    z_index = atoi(guy);
+    z[z_index] = g.wires[i].value;
+    if (max_z_index < z_index) max_z_index = z_index;
+  }
+
+  long answer = 0;
+  for (int i = max_z_index; i >= 0; i--) {
+    answer += z[i];
+    answer *= 2;
+  }
+
+  answer /= 2;
+
+  printf("Part 1: %ld", answer);
+
+  aoc_free();
+  exit(0);
+}