Trie is failing in Check function

Question

When it comes to checking a word, it seems like there is no connection between the nodes.

This where I am not getting the desired return. It's right under the check function.

if(checker -> childern[temp] != NULL){
        checker = checker -> childern[temp];

        printf("\not Null \n");
}

typedef struct node{
    bool is_word;
    struct node* childern[27];
}
node;
node* pointer;

int dictionarySize = 0;

bool check(const char* word)
{
    node* checker = pointer;
    for(int i = 0; i < strlen(word); i++){
        if(isalpha(word[i])){
            int temp = tolower(word[i]) - 'a';
            // printf("Check Letter: %d\n", temp);
            if(checker -> childern[temp] != NULL){
               checker = checker -> childern[temp];

               printf("\not Null \n");
            }

            else{
                    // printf("\nSize: %lu\n", strlen(word));
                    // printf("\ni: %d\n", i);

                    // printf("\nWe have a null\n");
                    return false;
                }
            }
    }

    return true;
}

/**
 * Loads dictionary into memory.  Returns true if successful else false.
 */
bool load(const char* dictionary)
{
    //Reading the dictionary
    FILE* book = fopen(dictionary, "r");
    if(book == NULL){
        printf("Unable to open the dictionary !");
        return false;
    }

    // Declaring nodes.
    node* root = calloc(1, sizeof(node));
    pointer = root;
    // root -> is_word = false;

    //First letter from dictionary
    int currentLetter = fgetc(book);
    int index;

    while(currentLetter != EOF ){

        if(currentLetter == '\n'){
            pointer -> is_word = true; //THIS NEEDS TO BE FIXED
            pointer = root;
            dictionarySize ++;

            printf("\n");
        }

        else if(isalpha(currentLetter)){
            index = tolower(currentLetter) - 'a';
            if(pointer -> childern[index] == NULL){
                pointer -> childern[index] = calloc(1, sizeof(node));
                pointer = pointer -> childern[index];

                //  printf("Letter: %c\n", index + 97);
            }

            else{
                pointer = pointer -> childern[index];
                // printf("No Null\n");
            }
        }
        currentLetter = fgetc(book);


    }
    if(!ferror(book)){
        fclose(book);
        return true;
    }
    else{
        fclose(book);
        return false;
    }


}

Answer 1

Your problem lies in what's not in the code - two oversights.

The code doesn't actually check is_word when it actually gets to the end of a word in the trie. Say that your dictionary had the words cat and caterpillar. Because it doesn't make the check, it would accept caterp as a word.

The code doesn't handle apostrophes. It gets by because, mathematically, it treats an apostrophe as an 'e', so the error is never exposed.

There may be other issues, but these are certainly the most important.

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