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CS50x Week 5 Update

Hermes
16, Self-Teaching, Junior Coder, Likes PC Hardware
・2 min read

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So I'm finally done with Week 5 in CS50x and moving in to Week 6(Python).

In the Problem Set for Week 5, We were tasked to build a spell-check application(using C) which spell-checks a file and lists out misspelled words(if any are found).

It might seem like an easy program to make with some other languages and yeah that's true but with C it wasn't so simple because you had to build your own -

  • Hash-Table(using Arrays and Linked List)
  • A custom Hash Function that hashes the words before they are stored in a Hash Table
  • A Linked List which is what holds the words in the Hash Table

And you still had to deal with Memory Management(which can be a pain) by writing a function that allocates and loads the words into memory and also writing a function that unloads(frees) the allocated memory at the end of the program.

But the entire problem turned out to be straightforward if you do it step-by-step. Most of the time i spent was dealing with memory leaks in my custom Hash-Function.

unsigned int hash(const char *word)
{
    //THIS HASH FUNCTION IS A MODIFIED VERSION OF THE ONE I GOT FROM THE SECOND ANSWER IN THIS STACK OVERFLOW POST - https://stackoverflow.com/questions/31366098/hash-function-c
    int sum = 0;

    char cpy[strlen(word) + 1];

    strcpy(cpy, word);
    for (int i = 0, n = strlen(cpy); i < n; i++)
    {
        cpy[i] = tolower(cpy[i]);
    }

    int i = 0;
    while (cpy[i] != '\0')
    {

        if (cpy[i] >= 'a' && cpy[i] < 'a' + 26)
        {
            sum = sum + (cpy[i] - 'a' + 1);
        }

        else
        {
            if (isalpha(cpy[i]))
            {
                sum += 0;
            }
        }

        i++;
    }
    return sum;
}
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My Hash Function was a modified version of one i got from a stack overflow post.

This problem set wasn't as hard as some previous ones, I spent less than a day on it and now I'm moving to Week 6(Python)..I will post another update when i finish Week 6.

IF YOU'RE INTERESTED IN HARVARD'S CS50X(INTRO TO COMPUTER SCIENCE), ENROLL HERE. IT'S FREE!!!

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