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@flare9x
Last active November 4, 2024 01:27
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CS50 Speller Solution
// 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);
// 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 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++)
{
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 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)
{
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++)
{
// 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
// 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;
}
@guyzilberblum
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How did you come to think about it? I find myself struggling to come up with a complete solution on my own, and I'm starting to wonder if perhaps programming is not the right path for me. Or could it be that I am just overreacting and exaggerating the situation? It's hard to tell sometimes if I'm just facing a temporary block or if this is a sign that I'm not cut out for it.

@Dyen1992
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Dyen1992 commented Nov 2, 2024

How did you come to think about it? I find myself struggling to come up with a complete solution on my own, and I'm starting to wonder if perhaps programming is not the right path for me. Or could it be that I am just overreacting and exaggerating the situation? It's hard to tell sometimes if I'm just facing a temporary block or if this is a sign that I'm not cut out for it.

@guyzilberblum I feel where you're coming from.
My friends were telling me to get into it since I took Cisco in high school but I can't seem to follow the process on some of these problems... ;{

@flare9x
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flare9x commented Nov 4, 2024 via email

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