feat: add hash_map data structure

fixes #3

test/hash_map_test.c

@@ -0,0 +1,27 @@
+#include "hash_map_test.h"
+
+void hash_map_test() {
+  struct hash_map *hash_map = hash_map_initialization();
+  assert(hash_map->length == 0);
+  hash_map_add(hash_map, "key", (void *)'a');
+  hash_map_add(hash_map, "key1", (void *)'b');
+  hash_map_add(hash_map, "key2", (void *)'c');
+  hash_map_add(hash_map, "key3", (void *)'d');
+  hash_map_add(hash_map, "key4", (void *)'e');
+  hash_map_add(hash_map, "key5", (void *)'f');
+  assert(hash_map->length == 6);
+  assert(hash_map_get(hash_map, "key") == (void *)'a');
+  assert(hash_map_get(hash_map, "key1") == (void *)'b');
+  assert(hash_map_get(hash_map, "key2") == (void *)'c');
+  assert(hash_map_get(hash_map, "key3") == (void *)'d');
+  assert(hash_map_get(hash_map, "key4") == (void *)'e');
+  assert(hash_map_get(hash_map, "key5") == (void *)'f');
+  hash_map_add(hash_map, "key5", (void *)'a');
+  assert(hash_map_get(hash_map, "key5") == (void *)'a');
+  assert(hash_map_contains_key(hash_map, "key5"));
+  assert(!hash_map_contains_key(hash_map, "invalid key"));
+  assert(hash_map_contains_key(hash_map, "key5"));
+  hash_map_remove(hash_map, "key5");
+  assert(hash_map->length == 5);
+  assert(!hash_map_contains_key(hash_map, "key5"));
+}

test/hash_map_test.h

@@ -0,0 +1,12 @@
+#ifndef __HASH_MAP_TEST__
+#define __HASH_MAP_TEST__
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "libcproject.h"
+
+void hash_map_test();
+
+#endif

test/main.c

@@ -5,6 +5,7 @@
 #include "character_test.h"
 #include "convert_test.h"
 #include "dictionary_test.h"
+#include "hash_map_test.h"
 #include "linked_list_test.h"
 #include "mathematics_test.h"
 #include "queue_test.h"
@@ -16,6 +17,7 @@ int main() {
   character_test();
   convert_test();
   dictionary_test();
+  hash_map_test();
   linked_list_test();
   mathematics_test();
   queue_test();