counting the number of sentences in a paragraph in c

Question

As part of my course, I have to learn C using Turbo C (unfortunately).

Our teacher asked us to make a piece of code that counts the number of characters, words and sentences in a paragraph (only using printf, getch() and a while loop.. he doesn't want us to use any other commands yet). Here is the code I wrote:

#include <stdio.h>
#include <conio.h>

void main(void)  
{  
clrscr();  
int count = 0;  
int words = 0;  
int sentences = 0;  
char ch;

while ((ch = getch()) != '\n')
{
    printf("%c", ch);
    while ((ch = getch()) != '.')
    {
        printf("%c", ch);
        while ((ch = getch()) != ' ')
        {
            printf("%c", ch);
            count++;
        }
        printf("%c", ch);
        words++;
    }
    sentences++;
}

printf("The number of characters are %d", count);
printf("\nThe number of words are %d", words);
printf("\nThe number of sentences are %d", sentences);
getch();
   }

It does work (counts the number of characters and words at least). However when I compile the code and check it out on the console window I can't get the program to stop running. It is supposed to end as soon as I input the enter key. Why is that?

Answer 1

Here you have the solution to your problem:

#include <stdio.h>
#include <conio.h>

void main(void)
{
    clrscr();  
    int count = 0;  
    int words = 0;  
    int sentences = 0;  
    char ch;

    ch = getch();
    while (ch != '\n')
    {
        while (ch != '.' && ch != '\n')
        {
            while (ch != ' ' && ch != '\n' && ch != '.')
            {
                count++;
                ch = getch();
                printf("%c", ch);
            }
            words++;
            while(ch == ' ') {
                ch = getch();
                printf("%c", ch);
            }
        }
        sentences++;
        while(ch == '.' && ch == ' ') {
           ch = getch();
           printf("%c", ch);
        }
    }

    printf("The number of characters are %d", count);
    printf("\nThe number of words are %d", words);
    printf("\nThe number of sentences are %d", sentences);
    getch();
}

The problem with your code is that the innermost while loop was consuming all the characters. Whenever you enter there and you type a dot or a newline it stays inside that loop because ch is different from a blank. However, when you exit from the innermost loop you risk to remain stuck at the second loop because ch will be a blank and so always different from '.' and '\n'. Since in my solution you only acquire a character in the innermost loop, in the other loops you need to "eat" the blank and the dot in order to go on with the other characters.

Checking these conditions in the two inner loops makes the code work. Notice that I removed some of your prints.

Hope it helps.

Edit: I added the instructions to print what you type and a last check in the while loop after sentences++ to check the blank, otherwise it will count one word more.