PSet5 case-insensitive using strcasecmp

Question

Tried iteration over strlen and random constant variable but unable to solve:

:( spell-checking is case-insensitive
    expected "MISSPELLED WOR...", not "MISSPELLED WOR..."

Here is my full code:

// Implements a dictionary's functionality

#include <stdbool.h>
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <stdlib.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 = 10000;

int word_count = 0;
bool dic_loaded = false;

// Hash table
node *table[N];

// Returns true if word is in dictionary else false
bool check(const char *word)
{
    int h = hash(word);
    node *cursor = table[h];
    for (int i = 0; i < 101; i++)
    {
        while (cursor != NULL)
        {
            if (strcasecmp(cursor->word, word) == 0)
            {
                return true;
            }
            else
            {
                cursor = cursor->next;
            }
        }
    }
    return false;
}

// Hashes word to a number
unsigned int hash(const char *word)
{
    int hash = 0;
    int n;
    for (int i = 0; word[i] != '\0'; i++)
    {
        if (isalpha(word[i]))
        {
            n = word[i] - 'a' + 1;
        }
        else
        {
            n = 27;
        }
    }
    return hash = ((hash << 3) + n) % N;
}

// Loads dictionary into memory, returning true if successful else false
bool load(const char *dictionary)
{
    FILE *file = fopen(dictionary, "r");
    if (file == NULL)
    {
        printf("Dictionary not found.\n");
        return false;
    }

    for (int i = 0; i < N; i++)
    {
        table[i] = NULL;
    }

    char word[LENGTH + 1];

    while((fscanf(file, "%s", word)) != EOF)
    {
        word_count++;
        node *n = malloc(sizeof(node));
        if (n == NULL)
        {
            printf("Malloc error.\n");
            return false;
        }
        strcpy(n->word, word);
        int h = hash(word);
        n->next = table[h];
        table[h] = n;
    }
    dic_loaded = true;
    fclose(file);
    return true;
}

// Returns number of words in dictionary if loaded else 0 if not yet loaded
unsigned int size(void)
{
    if (dic_loaded == true)
    {
        return word_count;
    }
    else
    {
    return 0;
    }
}

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

    }
    dic_loaded = false;
    return true;
}

I was unable to understand answers on other questions and was helpless. That's why I asked this question seperately.

Answer 1

Your word comparison appears to be case insensitive.

What about your hash function? Is it case sensitive? ;-)

If this answers your question, please click on the check mark to accept. Let's keep up on forum maintenance. ;-)