cs50/readability.c

#include <cs50.h>
#include <ctype.h>
#include <math.h>
#include <stdio.h>
#include <string.h>

int get_letters(string text);
int get_words(string text);
int get_sentences(string text);

int main(void)
{
    // Prompt the user for some text
    string text = get_string("Text:\n");

    // Count the number of letters, words, and sentences in the text
    int letters = get_letters(text);
    int words = get_words(text) + 1; // +1 for last word
    int sentences = get_sentences(text);

    // Compute the Coleman-Liau index
    int index = round(0.0588 * (100 * letters / (float) words) - 0.296 * (100 * sentences / (float) words) - 15.8);

    // Print the grade level
    if (index < 1)
    {
        printf("Before Grade 1\n");
    }
    else if (index >= 16)
    {
        printf("Grade 16+\n");
    }
    else
    {
        printf("Grade %i\n", index);
    }

    // printf("# letters:   %i\n", letters);
    // printf("# words:     %i\n", words);
    // printf("# sentences: %i\n", sentences);
}

int get_letters(string text)
{
    int letters = 0;
    for (int i = 0, length = strlen(text); i < length; i++)
    {
        if (!isspace(text[i]) && !ispunct(text[i]))
        {
            letters++;
        }
    }
    return letters;
}

int get_words(string text)
{
    int words = 0;
    for (int i = 0, length = strlen(text); i < length; i++)
    {
        if (isspace(text[i]))
        {
            words++;
        }
    }
    return words;
}

int get_sentences(string text)
{
    int sentences = 0;
    for (int i = 0, length = strlen(text); i < length; i++)
    {
        if (text[i] == '!' || text[i] == '?' || text[i] == '.')
        {
            sentences++;
        }
    }
    return sentences;
}