This is an implementation of a basic HashMap data structure written in C. HashMaps in C are a way of storing data in key-value pairs and provide efficient insertion, deletion and retrieval operations.

• This HashMap implementation uses chaining to resolve collisions.
• Basic operations such as insertion (insertToHashMap), deletion (removeFromHashMap), retrieval (getValueFromHashMap), and freeing the used memory (freeHashMap).
• A function to create a new HashMap (newHashMap).

• HashMap *newHashMap(int size);
• void insertToHashMap(HashMap *hashmap, char *key, char *value);
• char *getValueFromHashMap(HashMap *hashmap, char *key);
• void freeHashMap(HashMap *hashmap);
• int removeFromHashMap(HashMap *hashmap, char *key);

#include <stdio.h>

#include "hashmap.h"

int main(void) {
  int size = 100;
  HashMap *hashmap = newHashMap(size);

  insertToHashMap(hashmap, "key1", "value1");
  insertToHashMap(hashmap, "key1", "value2");
  insertToHashMap(hashmap, "key2", "value1");
  char *value = getValueFromHashMap(hashmap, "key1");
  printf("key1: %s\n", value);  // should be value2

  removeFromHashMap(hashmap, "key1");
  value = getValueFromHashMap(hashmap, "key1");
  printf("key1: %s\n", value);  // should be NULL

  freeHashMap(hashmap);
  return 0;
}

The HashMap implementation is contained in a single C source file. There are no external dependencies. Compile using your favorite C compiler.

MIT