I'm having some trouble in the pset5, I actually don't know how to start debugging, I've watched the lessons a few times now and I'm not getting anywhere..
When I run speller.c it is giving me a seg fault, I ran the debugger and it crashes at the beginning of the For Loop, here follows my code:
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <ctype.h>
#include <string.h>
#include "dictionary.h"
// default dictionary
#define DICTIONARY "dictionaries/large"
//created the struct node
typedef struct node
{
bool is_word;
struct node * paths[27];
}
node;
int letter = 0;
char * word = NULL;
/**
* Returns true if word is in dictionary else false.
*/
bool check(const char *word)
{
//todo
return false;
}
/**
* Loads dictionary into memory. Returns true if successful else false.
*/
bool load(const char *dictionary)
{
//opens dictionary for reading
FILE *fp = fopen(DICTIONARY, "r");
if (fp == NULL)
{
return false;
unload();
}
//creates the root of the trie
node *root = malloc(sizeof(node));
root -> is_word = false;
node * trav = root;
char * word = NULL;
//start reading the file
while (fscanf(fp, "%s", word) != EOF)
{
for (int i = 0; i < strlen(word); i++)
{
//assessing which path to take
char c = fgetc(fp);
if (isupper(c))
{
letter = tolower (c);
letter = letter -'a';
}
else if (isalpha(c))
{
letter = c;
letter = letter -'a';
}
else if (c == '\'')
{
letter = 26;
}
else if (c == '\0')
{
trav -> is_word = true;
}
if (trav -> paths[letter] == NULL)
{
node *new_node = malloc(sizeof(node));
if (new_node == NULL)
{
return false;
unload();
}
//point to new node
trav -> paths[letter] = new_node;
}
else
{
trav = trav -> paths[letter];
}
}
}
if (fscanf(fp, "%s", word) == EOF)
{
fclose(fp);
return true;
}
return false;
}
/**
* Returns number of words in dictionary if loaded else 0 if not yet loaded.
*/
unsigned int size(void)
{
// TODO
return 0;
}
/**
* Unloads dictionary from memory. Returns true if successful else false.
*/
bool unload(void)
{
// TODO
return false;
}
I also don't know how to point the new_node to the next new node and if I must have different names for them. For example, I'm going to store the word "foo", so I read the node called trav, go to the path[5] (the f letter), check if it is already opened, if not (if it's NULL) I create a node called new_node and point trav -> paths[5] to it, than I should update trav to be the new node, so I point it to it's own path[letter]?
