hash table

// Implements a dictionary's functionality

#include <stdio.h>
#include <ctype.h>
#include <stdbool.h>
#include <stdlib.h>
#include <strings.h>

#include "dictionary.h"

// Represents a node in a hash table
typedef struct node
{
    char word[LENGTH + 1];
    struct node *next;
} node;

// TODO: Choose number of buckets in hash table
const unsigned int N = 80;

// Hash table
node *table[N];

void free_list(struct node *n)
{
    while(n != NULL)
    {
        node *tmp = n->next;
        free(n);
        n = tmp;
    }
}

bool insert_node(struct node *w)
{
    unsigned int table_index = hash(w->word);
    if (table[table_index] == NULL)
    {
        table[table_index] = w;
        return true;
    }
    for (node *n = table[table_index]; n != NULL; n = n->next)
    {
        if (n->next == NULL)
        {
            n->next = w;
            return true;
        }
    }
    return false;
}

// Returns true if word is in dictionary, else false
bool check(const char *word)
{
    // TODO
    unsigned int word_hash = hash(word);
    for (node *n = table[word_hash]; n != NULL; n = n->next)
    {
        if (strcasecmp(n->word, word))
        {
            return true;
        }
    }
    return false;
}

// Hashes word to a number
unsigned int hash(const char *word)
{
    // TODO: Improve this hash function
    short ind = 0;
    unsigned int hash_val = 0;
    while (word[ind] != '\0')
    {
        if (isalpha(word[ind]))
        {
            hash_val += word[ind];
        }
        ind++;
    }
    return hash_val % N;
    // return tolower(word[0]) * tolower(word[1]) % N;
}

// Loads dictionary into memory, returning true if successful, else false
bool load(const char *dictionary)
{
    // TODO
    FILE *dict = fopen(dictionary, "r");
    if (dict == NULL)
    {
        printf("Could not open a dictionary file.\n");
        fclose(dict);
        return false;
    }

    node *word = malloc(sizeof(struct node));
    if (word != NULL)
    {
        printf("Starting loading dictionary\n");
        int char_index = 0;
        char c;
        while (fread(&c, sizeof(char), 1, dict))
        {
            if (isalpha(c) || (c == '\'' && char_index > 0))
            {
                word->word[char_index] = c;
                char_index++;
            }
            else if (c == '\n')
            {
                word->word[char_index + 1] = '\0';
                if (insert_node(word))
                {
                    node *next_word = malloc(sizeof(struct node));
                    if (next_word == NULL)
                    {
                        printf("Could not load next word.\n");
                        fclose(dict);
                        return false;
                    }
                    word->next = next_word;
                    word = next_word;
                    char_index = 0;
                }
            }
        }
        printf("LOADED!\n");
        fclose(dict);
        return true;
    }
    printf("Couldn't load dictionary\n");
    fclose(dict);
    return false;
}

// Returns number of words in dictionary if loaded, else 0 if not yet loaded
unsigned int size(void)
{
    // TODO
    printf("checking size\n");
    unsigned int elements = 0;
    for (int i = 0; i < N; i++)
    {
        for (node *j = table[i]; j != NULL; j = j->next)
        {
            elements++;
        }
    }
    printf("Returning size\n");
    return elements;
}

// Unloads dictionary from memory, returning true if successful, else false
bool unload(void)
{
    // TODO
    for (int i = 0; i < N; i++)
    {
        if (table[i] != NULL)
        {
            free_list(table[i]);
        }
    }
    return true;
}

/* void free_list(struct node *n)
{
    if(n == NULL)
    {
        return;
    }
    free_list(n->next);
    free(n);
    return;
} */
/* void insert_node(struct node *w)
{
    unsigned int table_index = hash(w->word);
    if (table[table_index] == NULL)
    {
        table[table_index] = w;
        return;
    }
    for (node *n = table[table_index]; n != NULL; n = n->next)
    {
        if (n->next == NULL)
        {
            n->next = w;
        }
    }
}