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Andrew Bannerman revised this gist
May 7, 2022 . 1 changed file with 6 additions and 16 deletions.There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -18,18 +18,6 @@ unsigned int count_words = 0; // Prototypes unsigned int size(void); // Represents a node in a hash table typedef struct node { @@ -84,7 +72,8 @@ unsigned int hash(const char *word) // new hash function // loop over each character in the string // square the uppe case ASCII number, sum each squared ASCII number and mod N // mid word perform another function unsigned int roll_sum = 0; unsigned int squared = 0; for (int i = 0; i < strlen(word); i++) @@ -104,7 +93,7 @@ bool load(const char *dictionary) { // TODO // add a method to sum the words as loading into dictionary // Open the dictionary file FILE *dict_open = fopen(dictionary, "r"); // pointer to the memory address of the input file //printf("pointer to memory address of the memory card %p \n", input_memory_card); if (dict_open == NULL) @@ -187,9 +176,10 @@ bool unload(void) // loop along the index positions for (int i = 0; i < N; i++) { // set temp and cursor to first index position node *temp = table[i]; node *cursor = table[i]; // at each index position // traverse the linked list at that index position and free - use temp/cursor // while loop until NULL -
May 7, 2022 .There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -0,0 +1,206 @@ // Implements a dictionary's functionality #include <ctype.h> #include <stdbool.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include <math.h> #include "dictionary.h" // make count_words a global variable // it may be called in size(); unsigned int count_words = 0; // Prototypes unsigned int size(void); // Helper functions // counting the words int count_help(char word[LENGTH + 1]) { int count = 0; if (strcmp(word, word) == 0) { count = 1; } return count; } // 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 // N = 26 this is A to Z const unsigned int N = 20000; // Hash table // a hash table is an array of linked lists node *table[N]; // * points to the first address // Returns true if word is in dictionary, else false bool check(const char *word) { // TODO // traverse the linked list searching for a matching word // word index position int word_index = hash(word); // initialize cursor to first node in the linked list // note cursor->word is current word // note cursor->next is a pointer to the next node address node *cursor = table[word_index]; // while loop to iterate until NULL // NULL is the one with no pointer while (cursor != NULL) { if (strcasecmp(word, cursor->word) == 0) { return true; // word is found } // set the cursor to the next node in the linked list cursor = cursor->next; } return false; } // Hashes word to a number unsigned int hash(const char *word) { // TODO: Improve this hash function // consider a function on each character in a word to insurace uniqueness however will output fit in N-1? // to fit N do module % N // output is the address in the linked list //return toupper(word[0]) - 'A'; // new hash function // loop over each character in the string // square the ASCII number, sum each squared ASCII number and mod N unsigned int roll_sum = 0; unsigned int squared = 0; for (int i = 0; i < strlen(word); i++) { squared = pow(toupper(word[i]), 2); if (i == round(strlen(word) / 2)) { roll_sum = roll_sum + round(sqrt(roll_sum)) + 17; } roll_sum = squared + roll_sum + 47; } return roll_sum % N; } // Loads dictionary into memory, returning true if successful, else false bool load(const char *dictionary) { // TODO // add a method to sum the words as loading into dictionary // Open the disctionairy file FILE *dict_open = fopen(dictionary, "r"); // pointer to the memory address of the input file //printf("pointer to memory address of the memory card %p \n", input_memory_card); if (dict_open == NULL) { printf("Could not open the dictionary file.\n"); return false; } else if (dict_open != NULL) { char buffer[LENGTH + 1]; int hash_index = 0; while (fscanf(dict_open, "%s", buffer) != EOF) { //printf("yee %s \n",buffer); // Create a new node for the word the size of the node // enough bytes for the word itselt and the address node *n = malloc(sizeof(node)); // check that the memory initialized ok if (n == NULL) { return false; break; } else if (n != NULL) { // copy the word into the word portion of the node strcpy(n->word, buffer); // set address to NULL n->next = NULL; // testing the hash function //printf("testing hash function %i \n", hash(buffer)); // get the hash number hash_index = hash(buffer); // case 1 - the first entry // if nothing is there equal the first entry to the new node if (table[hash_index] == NULL) { table[hash_index] = n; } // case 2 - an entry already exists // inserts at the front of the linked list each time else if (table[hash_index] != NULL) { // set the new node address to the first element index position n->next = table[hash_index]; // set the head of the linked list to the previously inserted node table[hash_index] = n; } // count words count_words++; } } // end while loop fclose(dict_open); return true; } else { return false; } } // Returns number of words in dictionary if loaded, else 0 if not yet loaded unsigned int size(void) { // TODO // summed count words whilst loading return count_words; } // Unloads dictionary from memory, returning true if successful, else false bool unload(void) { // TODO // tmp and curosr method move cursor->cursor->next. free temp.. cursor->next...NULL // loop along the index positions for (int i = 0; i < N; i++) { node *temp = table[i]; node *cursor = table[i]; // set temp and cursor to first index position // at each index position // traverse the linked list at that index position and free - use temp/cursor // while loop until NULL // at that point next i will begin while (temp != NULL) { // set cursor to next cursor = cursor->next; // i+1 free(temp); temp = cursor; } } return true; }
Andrew Bannerman
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