CS50 Pset5 : code cannot compile because of linker failure - c

Question

I just finish writing a simple code for Pset5 speller just to check if my code is able to compile. The code is written into the header file. However, when I try to compile the file the error clang-7: error: linker command failed with exit code 1 shows up. Based on my shallow understanding of what have read online, it says that this error would occur if I declare and call a function that does not have any definition. Any help would be much appreciated. Here is my code:
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include "dictionary.h"
// Represents a node in a hash table
typedef struct node
{
char word[LENGTH + 1];
struct node *next;
}
node;
// Number of buckets in hash table
const unsigned int N = 26;
// Hash table
node *table[N];
// Returns true if word is in dictionary else false
//uses the hash table to check
bool check(const char *word)
{
int hashindex = hash(word);
node *tmp = table[hashindex];
while (tmp->next != NULL)
{
if (strcmp(word, tmp->word) == 0)
{
return true;
}
tmp = tmp->next;
}
return false;
}
// Hashes word to a number
unsigned int hash(const char *word)
{
//hashing the first letter of the string
unsigned int value1 = (int) *(word);
unsigned int value2;
if (isupper(value1))
{
value2 = tolower(value1);
}
else
{
value2 = value1;
}
int hashvalue = value2 % 97;
return hashvalue;
}
// Loads dictionary into memory, returning true if successful else false
//hashes the words in the dictionary file
bool load(const char *dictionary)
{
// open dictionary file to load
FILE *file = fopen(dictionary, "r");
if (file == NULL)
{
printf("Could not open %s.\n", dictionary);
return false;
}
//making an array that can store scanned words from the dictionary
char dictionaryword[LENGTH];
//initializing all the buckets in the table
for (int i = 0; i < N; i++)
{
table[i] = NULL;
}
//loop to read the word one-by-one
while(fscanf(file, "%s", dictionaryword) != EOF)
{
//creating a new node to store the word
node *n = malloc(sizeof(node));
if (n == NULL)
{
return false;
}
strcpy(n->word, dictionaryword);
n->next = NULL;
//hashing the word to determine which bucket to store it in
int hashindex = hash(n->word);
//checking for any collisions
if (table[hashindex] == NULL)
{
table[hashindex] = n;
}
else
{
//adding new node from the end
node *tmp = table[hashindex];
while (tmp->next != NULL)
{
tmp = tmp->next;
}
tmp->next = n;
}
memset (dictionaryword, 0, LENGTH);
}
return true;
}
// Returns number of words in dictionary if loaded else 0 if not yet loaded
//the biggest number in the hash table
unsigned int size(void)
{
//iterate over each bucket, assuming all the buckets are filled
unsigned int counter = 0;
for (int i = 0; i < N; i++)
{
node* tmp = table[i];
while(tmp->next != NULL)
{
tmp = tmp->next;
counter++;
}
}
return counter;
}
// Unloads dictionary from memory, returning true if successful else false
bool unload(void)
{
for (int i = 0; i < N; i++)
{
//if the bucket is not filled, memory is leaked somewhere
if (table[i] == NULL)
{
return false;
}
while (table[i] != NULL)
{
node *tmp = table[i]->next;
free(table[i]);
table[i] = tmp;
}
}
return true;
}
EDIT: This is the header file
#ifndef DICTIONARY_H
#define DICTIONARY_H
#include <stdbool.h>
// Maximum length for a word
// (e.g., pneumonoultramicroscopicsilicovolcanoconiosis)
#define LENGTH 45
// Prototypes
bool check(const char *word);
unsigned int hash(const char *word);
bool load(const char *dictionary);
unsigned int size(void);
bool unload(void);
#endif // DICTIONARY_H