My program works fine with the small dictionary. But when I attempt to load the large library it gets a segmentation fault when loading the 1908th dictionary word. The code that I am using is below. I've isolated the problem at the node* new_node = malloc(sizeof(node)) statement. I'm at wits end trying to understand what is the problem.

/** * Loads dictionary into memory. Returns true if successful else false. */

bool load(const char* dictionary) {

char word[LENGTH + 1] = "                                              ";

//initialize hash table
char blankWord[LENGTH + 1] = "                                              ";

for (int i = 0; i < 500; i++)

    hashTable[i] = malloc(sizeof(node));
    strcpy(hashTable[i]->word, blankWord);
    hashTable[i]->next = NULL;

// open dictionary as input
FILE* infile = fopen(dictionary, "r");

// if no file opened, return an error.
if (infile == NULL)
    return false;

// until end of dictionary entries
while(fscanf(infile, "%s", word) != EOF)
    int hashKey = getHashKey(word);
    node* new_node = malloc(sizeof(node));

    strcpy(new_node->word, word);

    if(hashTable[hashKey]->next == NULL)

        new_node->next = NULL;           
        hashTable[hashKey]->next = new_node;        

        new_node->next = hashTable[hashKey]->next;           
        hashTable[hashKey]->next = new_node;

2 Answers 2


Your code loads the small dictionary which only has a few words, but your dictionary, as written, will not be efficiently searchable, and will almost certainly contain memory leaks. Here are some questions to think about:

  1. why bother initializing word and blankword as " " when you can just declare them?

  2. how is getHashKey() function defined? I assume it assigns a word to the right node of your hashtable based on its first letter. If so, why do you have i<500 when there are only 26 letters in the alphabet?

  3. related to #2 above, review the lecture to see how hash table nodes are initialized

  • 1.)I'm using blankWord to intialize my hashtable->word variables. When I set it to NULL I immediately got a segmentation fault. 2.) My hashtable has 500 buckets. I perform an arithmetic operation on the characters and then mod 500 the result 3.) I've tried to initialize the table several ways. The way I have it now it at least loads the first 1907 words from the large dictionary. I'm not sure why it gets a segmentation fault after loading the 1908th word. valgrind didn't find any memory leaks. Commented Feb 14, 2015 at 6:29

Finally after two days. After allocating the new node, instead of initializing the .word variable, I let it default. I still initialized the .next variable with NULL. This seems to have resolved my issue. Whew! Wiping sweat from brow.

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