Why is my integer variable being added to my other integer variable? - cs50

Question

I am writing a program that counts the amount of letters and words in a string given by the user. For some reason, the number of words is being added to the number of letters. If there is 3 words in the sentence and 12 letters, then it says that there is 15 words. My code is below:
#include <cs50.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
int storeLetters[] = {};
int storeWords[] = {};
// declare functions
int count_letters(string text);
int count_words(string text);
int main(void)
{
// ask user for text passage
string text = get_string("Text: ");
int numOfLetters = count_letters(text);
printf("%d",numOfLetters);
printf(" letters\n");
int numOfWords = count_words(text);
printf("%d",numOfWords);
printf(" words\n");
}
int count_letters(string text)
{
int amountOfLetters = 0;
for (int i = 0, n = strlen(text); i < n; i++)
{
if (isalpha(text[i]))
{
storeLetters[i] += 1;
amountOfLetters += storeLetters[i];
}
else
{
storeLetters[i] += 0;
amountOfLetters += storeLetters[i];
}
}
return amountOfLetters;
}
int count_words(string text)
{
int amountOfWords = 0;
for (int x = 0, n = strlen(text); x < n; x++)
{
if (text[x] == '?' || text[x] == '!' || text[x] == '.' || text[x] == ' ')
{
storeWords[x] += 1;
amountOfWords += storeWords[x];
}
else
{
storeWords[x] += 0;
amountOfWords += storeWords[x];
}
}
return amountOfWords;
}

Answer 1

storeLetters and storeWords are arrays, which you initialize to zero length. If you access storeLetters[0] (or any other index), you go past the end. It's not gonna work.
You don't need those variables at all. Just increment amountOfLetters directly.
int count_letters(string text)
{
int amountOfLetters = 0;
for (int i = 0, n = strlen(text); i < n; i++)
{
if (isalpha(text[i]))
{
amountOfLetters += 1;
}
}
return amountOfLetters;
}