String won't store more than one word (C) - arrays

Question

This is the first step in a program I have written.
The objective: A user needs to write a sentence, and my program needs to store it in an array. This can be as short or long as they like.
My program: Runs with no technical errors
The issue: When I run the program, I am unable to submit anything more than 1 word. 'Hello' submits and the program executes. Anything more than that - new words, spaces, punctuation and numbers, when I hit enter - I just keep jumping to a new line in my terminal and the program doesn't go to the next step.
This is the code I am using to
Prompt the user for text and
Store the answer.
#include <cs50.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
int main(void)
{
string z = get_string("Text: \n");
// int n = strlen(z);
int a = 0;
int d = 1;
int e = 0;
while (z[a] != '\0')
{
while (isalpha(z[a]))
{
a++;
}
while (z[a] ==' ')
{
d++;
}
//Count the sentences
while (z[a] == '.' || z[a] == '!' || z[a] == '?' || z[a] == '/')
{
e++;
}
}
// printf("%i letter(s)\n", a);
// printf("%i word(s)\n", d);
// printf("%i sentence(s)\n", e);
//Coleman-Liau index formula
int m = (0.0588 * (100 * a / d) - 0.206 * (100 * e / d) - 15.8);
if (m <= 1)
{
printf("Before Grade 1\n");
}
if (m >= 16)
{
printf("Grade 16+\n");
}
if (m < 16)
{
printf("Grade %i\n", m);
}
}
Pretty new to coding and any help will be appreciated!
Screenshot of my terminal

Answer 1

The problem is that the while loops that count words and sentences never increment a, which is the index into z. So they keep testing the same character over and over and you're in an infinite loop.
It works for a single word because those tests never succeed in the first place.
You also shouldn't be using the variable that counts letters as the array index.
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
int main(void)
{
char *z = get_string("Text: \n");
// int n = strlen(z);
int i = 0;
int a = 0;
int d = 1;
int e = 0;
while (z[i] != '\0')
{
int counted = 0;
while (isalpha(z[i]))
{
a++;
i++;
counted = 1;
}
while (z[i] ==' ')
{
d++;
i++;
counted = 1;
}
//Count the sentences
while (z[i] == '.' || z[i] == '!' || z[i] == '?' || z[i] == '/')
{
e++;
i++;
counted = 1;
}
if (!counted) {
i++;
}
}
// printf("%i letter(s)\n", a);
// printf("%i word(s)\n", d);
// printf("%i sentence(s)\n", e);
//Coleman-Liau index formula
int m = (0.0588 * (100 * a / d) - 0.206 * (100 * e / d) - 15.8);
if (m <= 1)
{
printf("Before Grade 1\n");
}
if (m >= 16)
{
printf("Grade 16+\n");
}
if (m < 16)
{
printf("Grade %i\n", m);
}
}

Answer 2

the following proposed code:
cleanly compiles using: gcc -Wall -Wextra -Wconversion -pedantic -std=gnu11 -c "untitled2.c" -o "untitled2.o"
performs the desired functionality
uses meaningful variable names
uses a unique variable name for stepping through the text
does not include header files those contents are not used
uses a for() loop for stepping through the text
uses size_t rather than int variables because the contents of those variables will never be <0
and now the proposed code:
#include <cs50.h>
#include <stdio.h>
//#include <string.h>
//#include <math.h>
#include <ctype.h>
int main(void)
{
string z = get_string("Text: \n");
size_t spaces = 0;
size_t sentences = 0;
size_t letters = 0;
for( size_t i = 0; z[i]; i++ )
{
if( z[i] ==' ' )
{
spaces++;
}
if( isalpha( z[i] ) )
{
letters++;
}
//Count the sentences
if( z[i] == '.' || z[i] == '!' || z[i] == '?' || z[i] == '/')
{
sentences++;
}
}
// printf("%i letter(s)\n", a);
// printf("%i word(s)\n", d);
// printf("%i sentence(s)\n", e);
//Coleman-Liau index formula
int m = (int)(0.0588 * (double)(100 * letters / spaces) - 0.206 * (double)(100 * sentences / spaces) - 15.8);
if (m <= 1)
{
printf("Before Grade 1\n");
}
if (m >= 16)
{
printf("Grade 16+\n");
}
if (m < 16)
{
printf("Grade %i\n", m);
}
}
a typical run of the program:
Text:
a quick brown fox jumped over a lazy dog
Grade 7