// Implements a dictionary's functionality

#include <stdbool.h> #include <cs50.h> #include <stdlib.h> #include <stdio.h> #include "dictionary.h" #include <string.h> #include <ctype.h>

#define HASHTABLE_SIZE 10000

unsigned int hash(const char *hash_this); // Represents a node in a hash table typedef struct node { char word[LENGTH + 1]; struct node *next; } node; int values = 0; // Number of buckets in hash table const unsigned int N = 10000;

// Hash table node *table[N];

// Returns true if word is in dictionary, else false bool check(const char *word) { // TODO

char low_word[LENGTH + 1]; for (int i = 0; i < LENGTH; i++) { if (isalpha(word[i])) { low_word[i] = tolower(word[i]); } } int hash_index = hash(low_word); node *cursor = table[hash_index] -> next; if (cursor -> next != NULL) { while (cursor -> next != NULL) { if (cursor -> word == low_word) { return true; } else { cursor = cursor -> next; } } return false; } else { return false; } 

}

// Hashes word to a number unsigned int hash(const char *hash_this) { unsigned int hash = 0; for (int i = 0, n = strlen(hash_this); i < n; i++) { hash = (hash << 2) ^ hash_this[i]; } return hash % HASHTABLE_SIZE; }

// Loads dictionary into memory, returnina true if successful, else false bool load(const char *dictionary) { // TODO FILE *dict = fopen(dictionary, "r"); if (dict == NULL) { printf("Invalid Dictionary\n"); return false; } values = 0; char word[LENGTH + 1]; while (fscanf(dict, "%s", word) != EOF) { for (int i = 0; i < LENGTH; i++) { if (isalpha(word[i])) { word[i] = tolower(word[i]); } }

 node *newNode = malloc(sizeof(node)); if (newNode == NULL) { return false; } strcpy(newNode -> word, word); newNode -> next = NULL; int hash_index = hash(newNode -> word); node *head = table[hash_index]; if (head -> next != NULL) { newNode -> next = head -> next; } head -> next = newNode; values++; } return true; 

}

// Returns number of words in dictionary if loaded, else 0 if not yet loaded unsigned int size(void) { // TODO return values; }

// Unloads dictionary from memory, returning true if successful, else false bool unload(void) { // TODO for (int i = 0; i < N; i++) { node *cursor = table[i] -> next; if (cursor != NULL) { node *tmp = cursor; cursor = cursor -> next; free(tmp -> next); } } if (sizeof(table) == sizeof(node[N])) { return true; } else { return false; } }

// Implements a dictionary's functionality #include <stdbool.h> #include <cs50.h> #include <stdlib.h> #include <stdio.h> #include "dictionary.h" #include <string.h> #include <ctype.h> #define HASHTABLE_SIZE 10000 unsigned int hash(const char *hash_this); // Represents a node in a hash table typedef struct node { char word[LENGTH + 1]; struct node *next; } node; int values = 0; // Number of buckets in hash table const unsigned int N = 10000; // Hash table node *table[N]; // Returns true if word is in dictionary, else false bool check(const char *word) { // TODO char low_word[LENGTH + 1];  for (int i = 0; i < LENGTH; i++)   {   if (isalpha(word[i]))   {   low_word[i] = tolower(word[i]);   }   }  int hash_index = hash(low_word);  node *cursor = table[hash_index] -> next;  if (cursor -> next != NULL)  {   while (cursor -> next != NULL)   {   if (cursor -> word == low_word)   {   return true;   }   else   {   cursor = cursor -> next;   }   }   return false;  }  else  {   return false;  }  } // Hashes word to a number unsigned int hash(const char *hash_this) { unsigned int hash = 0; for (int i = 0, n = strlen(hash_this); i < n; i++) { hash = (hash << 2) ^ hash_this[i]; } return hash % HASHTABLE_SIZE; } // Loads dictionary into memory, returnina true if successful, else false bool load(const char *dictionary) { // TODO FILE *dict = fopen(dictionary, "r"); if (dict == NULL) { printf("Invalid Dictionary\n"); return false; } values = 0;  char word[LENGTH + 1]; while (fscanf(dict, "%s", word) != EOF) { for (int i = 0; i < LENGTH; i++) {  if (isalpha(word[i])) { word[i] = tolower(word[i]); } } node *newNode = malloc(sizeof(node));   if (newNode == NULL)   {   return false;   }   strcpy(newNode -> word, word);   newNode -> next = NULL;   int hash_index = hash(newNode -> word);   node *head = table[hash_index];   if (head -> next != NULL)   {   newNode -> next = head -> next;   }   head -> next = newNode;   values++;  }  return true; }  // Returns number of words in dictionary if loaded, else 0 if not yet loaded unsigned int size(void) { // TODO return values; } // Unloads dictionary from memory, returning true if successful, else false bool unload(void) { // TODO for (int i = 0; i < N; i++) { node *cursor = table[i] -> next; if (cursor != NULL) { node *tmp = cursor; cursor = cursor -> next; free(tmp -> next); } } if (sizeof(table) == sizeof(node[N])) { return true; } else { return false; } }