Build a hacky hash table

3 files changed, 51 insertions, 1 deletions

diff --git a/src/02/04/hash.c b/src/02/04/hash.c
index c1a2bf9..9986173 100644
--- a/src/02/04/hash.c
+++ b/src/02/04/hash.c
@@ -1,7 +1,31 @@
 #include "hash.h"
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int to_hash(int key)
+{
+  return key % 13;
+}
 
 Hash *hash_init(int size)
 {
-  return NULL;
+  Hash *hash = malloc(sizeof(Hash));
+  hash->size = size;
+  return hash;
+}
+
+int hash_get(Hash *hash, int key)
+{
+  int bucket = to_hash(key);
+  Node node = hash->buckets[bucket];
+  return node.data;
+}
+
+void hash_set(Hash *hash, int key, int value)
+{
+  int bucket = to_hash(key);
+  Node node = hash->buckets[bucket];
+  node.data = value;
+  return;
 }
diff --git a/src/02/04/hash.h b/src/02/04/hash.h
index 6301584..b87f06c 100644
--- a/src/02/04/hash.h
+++ b/src/02/04/hash.h
@@ -1,4 +1,13 @@
+typedef struct node {
+  struct node *next;
+  int data;
+} Node;
+
 typedef struct {
+  Node buckets[13];
+  int size;
 } Hash;
 
 Hash *hash_init(int size);
+int hash_get(Hash *hash, int key);
+void hash_set(Hash *hash, int key, int value);
diff --git a/src/02/04/hash_test.c b/src/02/04/hash_test.c
index 6eeaebd..9073897 100644
--- a/src/02/04/hash_test.c
+++ b/src/02/04/hash_test.c
@@ -12,10 +12,27 @@ Ensure(HashTable, when_initializing_a_hash) {
   assert_that(hash, is_not_equal_to(NULL));
 }
 
+Ensure(HashTable, when_getting_a_value_for_a_key_that_has_not_been_inserted) {
+  Hash *hash = hash_init(13);
+
+  assert_that(hash_get(hash, 1), is_equal_to(NULL));
+}
+
+Ensure(HashTable, when_getting_a_values_for_a_key_that_has_been_inserted) {
+  int key = 7;
+  int value = 100;
+  Hash *hash = hash_init(13);
+
+  hash_set(hash, key, value);
+  assert_that(hash_get(hash, key), is_equal_to(value));
+}
+
 TestSuite *hash_table_tests() {
   TestSuite *suite = create_test_suite();
 
   add_test_with_context(suite, HashTable, when_initializing_a_hash);
+  add_test_with_context(suite, HashTable, when_getting_a_value_for_a_key_that_has_not_been_inserted);
+  add_test_with_context(suite, HashTable, when_getting_a_values_for_a_key_that_has_been_inserted);
   return suite;
 }