Created file for hash table dictionary

Author: ashish-ratn

hash.c

@@ -0,0 +1,100 @@
+#include "dict.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+/* simple constructor */
+Dictionary *create_dict(void)
+{
+    Dictionary *p_dic = malloc(sizeof(Dictionary));
+    if (p_dic)
+    {
+        p_dic->number_of_elements = 0;
+
+        /* initializes the elemens of the array with NULL-pointer */
+        for (int i = 0; i < MAXELEMENTS; i++)
+        {
+            p_dic->elements[i] = NULL;
+        }
+
+        return p_dic;
+    }
+    else
+    {
+        printf("unable to create a dictionary\n");
+        return NULL;
+    }
+}
+
+/*
+    utility function
+    sdbm hash algorithm
+    returns a hashcode for the given string 's'
+*/
+int get_hash(char s[])
+{
+    unsigned int hash_code = 0;
+
+    /* iterates over string at each character */
+    for (int counter = 0; s[counter] != '\0'; counter++)
+    {
+        /* actual computing of the hash code */
+        hash_code =
+            s[counter] + (hash_code << 6) + (hash_code << 16) - hash_code;
+    }
+
+    /* % modulo is for fitting the index in array. */
+    return hash_code % MAXELEMENTS;
+}
+
+int add_item_label(Dictionary *dic, char label[], void *item)
+{
+    unsigned int index = get_hash(label);
+
+    /* make sure index is fitting */
+    if (index < MAXELEMENTS)
+    {
+        dic->elements[index] = item;
+        return 0;
+    }
+
+    /* error case */
+    return -1;
+}
+
+int add_item_index(Dictionary *dic, int index, void *item)
+{
+    /* make sure whether this place is already given */
+    if (!dic->elements[index])
+    {
+        dic->elements[index] = item;
+        return 0;
+    }
+
+    /* error case */
+    return -1;
+}
+
+void *get_element_label(Dictionary *dict, char s[])
+{
+    int index = get_hash(s);
+    if (dict->elements[index])
+    {
+        return dict->elements[index];
+    }
+
+    printf("None entry at given label\n");
+    return NULL;
+}
+
+void *get_element_index(Dictionary *dict, int index)
+{
+    if (index >= 0 && index < MAXELEMENTS)
+    {
+        return dict->elements[index];
+    }
+
+    printf("index out of bounds!\n");
+    return NULL;
+}
+
+void destroy(Dictionary *dict) { free(dict); }