Help moving cursor in speller check()

Question

I have the dictionary loaded, and the first part of check done but -

1. I cannot move the cursor properly.
2. strcmp is not working properly. I tested it alone in another file and it did work. It is just not here.

It is in the block near the bottom that I think the problem is, moving through the list.

if(strcmp(arr, head->word) == 0)
          {
             puts("equal");
             return 0;
          } 
 //try to set the cursor to it's own next value (not sure if U can do this?)

      1.    cursor = cursor->next;

                   OR
  //keep moving head and pointer cursor to head ->next
      2.    cursor = head -> next
  //reset head to 2nd node, and so on
            head = cursor;

Both of the two attempts to move the cursor print out the same values.

The dictionary prints fine with ethier syntax

printf("dictionary word:%s\n",cursor->word)

But the text is not working. It prints each word multiple times. Like 100x each. No idea why.

printf("text word:%s", arr)

Check() function

     #include "dictionary.h"

    int hashValue(const char *word);


    typedef struct node
     {
     char word[LENGTH + 1];
    struct node *next;
     }
     node;

    node *hash_table[HASHTABLE_SIZE] = {NULL};

    // Returns true if word is in dictionary else false
    bool check(const char *word)
    {
       char arr[LENGTH+1];

     // HASH VALUE
    //     hash to get bucket/array index
      int hash_index = hashValue(word);
    // set head to first node in bucket/array
     node *head = hash_table[hash_index];

    // SET WORD TO LOWER
     for(int i = 0; i < strlen(word);i++)
     {
    arr[i] = tolower(word[i]);
      }
      // printf("string: %s\n", arr);
     // set cursor originally to head

       node *cursor = head;
      while(cursor != NULL)
    {

      if(strcmp(arr, head->word) == 0)
      {
         puts("equal");
         return 0;
      }
        cursor = head->next;
        printf("%s\n", arr);
        head = cursor;

    }
    return true;
}

Full file with load() if this if needed https://gist.github.com/chrisdel101/f34af62bd75454fe8511ec3750498556

Answer 1

There are a number of issues in the code that are causing issues. Here are the ones I spotted, there are probably more.

Check:

The word is being hashed without converting to all lower case. If there's a capital letter, it will return a different hash value.

The end of string marker isn't being stored in arr.

If strcmp results in a match, it returns 0, which is correctly checked. HOWEVER, the code then goes on to return 0;. Check is supposed to return a bool. When a number is returned, a 0 is treated as false and a non-zero is treated as true. That means that when the code finds a match, the code returns false. ALWAYS return true or false for a bool, never a number!

Hash function:

return hash % sizeof(HASHTABLE_SIZE);

The value sizeof(HASHTABLE_SIZE) returns the size of the constant HASHTABLE_SIZE, not the value that it represents. In other words, it will always be 4. You probably want this:

return hash % HASHTABLE_SIZE;

There are other issues, but its important that you work through the debugging process and sharpen your skills. If, after fixing these and working on it further, you get stuck, please post a new question.

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