Thread: Problem with limiting inputs of char functions

Code:

#include <stdio.h>
#define MAX_INPUT_LENGTH 80

int is_palindrome(char []);

int main(void)
{
	int i = 0, indicator = 0;
	char words[MAX_INPUT_LENGTH] = {'a'};

	do
	{
		do
		{
			scanf("%c", &words[i]);
			
			i++;
		} while(words[i] != '\n');
		
		indicator += is_palindrome(words);

	} while(words[i] != '\n' && words[i-1] != '\n');

	return 0;
}

int is_palindrome(char arr[])
{
	int max, max_temp, i;

	for(i = 0; i < MAX_INPUT_LENGTH; i++)
	{
		if(arr[i] == '\n')
		{
			max = i - 1;
			max_temp = max;
			break;
		}
	}

	for(i = 0; i < max / 2 + 1; i++)
	{
		if(arr[i] != arr[max_temp])
			return 0;
		else
			max_temp--;
	}

	return 1;
}

Hi all, I am trying to input a few sentences and check if each sentence is a palindrome without the spaces, commas and other which means we only take into account of alphabets (a-z or A-Z) e.g.
A car, a man, a maraca.
A nut for a jar of tuna.
Are we not drawn onward to new era?

It should give output 3 e.g. the number of palindrome sentences entered.
A enter with nothing for the line will end it.

However, I am not sure how to filter out the spaces and other non-alphabets as inputs, plus my while statements which are aimed at ending inputs when there is an empty line does not seem to work but I felt that it would work. Anyone can explain to me why it does not work?

I want him to enter
"text\n"
"text\n"
"text\n"
"\n" // type this to exit
3 // output if all 3 sentences are palindromes