#define AOC_HASHMAP_RADIX 1024

int aoc_hash(const char *string) {
  int len = strlen(string);
  int hash = 1;
  for (int i = 0; i < len; i++) {
    hash *= 7;
    hash += string[i] * 13;
    hash %= AOC_HASHMAP_RADIX;
  }

  return hash;
}

typedef struct AocHashmapNode AocHashmapNode;

typedef struct AocHashmapNode {
  char *key;
  long value;
  AocHashmapNode *next;
} AocHashmapNode;

typedef struct AocHashmap {
  AocHashmapNode* buckets[AOC_HASHMAP_RADIX];
} AocHashmap;

AocHashmapNode *aoc_hashmap_get(AocHashmap *map, char *key) {
  int hash = aoc_hash(key);
  AocHashmapNode *node = map->buckets[hash];
  while (node != NULL && strcmp(node->key, key) != 0) node = node->next;
  return node;
}

void *aoc_hashmap_put(AocHashmap *map, char *key, long value) {
  int hash = aoc_hash(key);
  AocHashmapNode *node = map->buckets[hash];
  while (node != NULL) node = node->next;
  map->buckets[hash] = malloc(sizeof(AocHashmapNode));
  node = map->buckets[hash];
  node->key = malloc(strlen(key) + 1);
  strcpy(node->key, key);
  node->value = value;
  node->next = NULL;
}