dictionary.c - shared from CS50 IDE

dictionary.c

/**
 * Loads dictionary into memory. Returns true if successful else false.
 */
bool load(const char *dictionary)
{
    // allocating space for root node
    root = calloc(1, sizeof(node));
    
    // assigning node pointer "temp" 
    temp = root;
    
    fd = fopen(dictionary, "r");
    
    // ensuring filepointer points to our dictionary
    if (fd == NULL)
    {
        fprintf(stderr, "Could not load dictionary.\n");
        return 1;
    }
    
    else
    {
        // iterates over the entire dictionary file
        for (int ch = fgetc(fd); ch != EOF; ch = fgetc(fd))
        {
            /**converts chars to corresponding array spots 
             * skipping node[0] to avoid conflict with '\0' null terminators
             * and skipping node[10] by assigning 'j'/10 to the end of 
             * the alphabet to avoid conflict with /n ASCII values
             */
            
            if (isalpha(ch))
            {
                ch = ch - 96;
                if (ch == 10)
                {
                    ch = 27;
                }
            }
            
            // assigning apostrophe characters to the end of the array
            else if (ch == '\'')
            {
                ch = 28;
            }
            
            // if the corresponding slot in the node is NULL
            if  (temp -> paths[ch] == NULL)
            {
                /** the end of a dictionary word 
                 * set the node bool to true and 
                 * reset the pointer to the root
                 */ 
                if (ch == '\n')
                {   
                    temp -> validword = true;
                    temp = root;    
                }
                
                // otherwise we're in the middle of a word
                else
                {
                    // call memory for a new node and have the slot in temp point to the new node
                    temp->paths[ch] = calloc(1, sizeof(node));
                    // temp pointer moves to new node
                    temp = temp -> paths[ch]; 
                }
                
            }
            
            // if the corresponding slot is already open        
            else if (temp -> paths[ch] != NULL)
            {   
               
                // temp pointer moves to the next node
                temp = temp -> paths[ch];
                
            }
            
        }   
            /** dictionary is loaded, so return pointer to the start 
             * of the file to prepare for spell check and return true
             */
            fseek(fd, 0, SEEK_SET);
            return true;
    }    
    // otherwise nothing was loaded and return false
    return false;
}