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C loop, giving me trouble !! Can anyone help..?


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4 replies to this topic

#1 rossen


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Posted 11 June 2008 - 04:03 AM

i have this code to test for palindromes, it functions perfectly well on the first test, but as the program continues to check for more after the first word it keeps printing not palindrome, once it wasnt the first word typed, run it pls, and you'll c what im talking about. Can anyone help me fix it..?

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

int isPalindrome( char *s);
int main (void)
int i=0;
int ch;
char s[100];
while (1){
while ((ch = getchar()) != ('\n')){
if (isalpha(ch)){
if (isPalindrome(s) ==1){
printf("is palindrome\n");
printf("not palindrome\n");
return 0;


Edited by v0id, 11 June 2008 - 05:13 AM.

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#2 Chinmoy


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Posted 11 June 2008 - 04:34 AM

Where is ispalindrome() defined?
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#3 WingedPanther73


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Posted 11 June 2008 - 08:08 AM

In your loop, you are continually incrementing i, so s will become something like the following:
s = "something\0else\0than\0expected\0"

You can see where you'll get issues.
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#4 revealer


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Posted 11 June 2008 - 09:28 AM

I can't see isPalindrome() nor isAlpha() anywhere.
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#5 Xav


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Posted 11 June 2008 - 10:45 AM

Presumably the functions are defined elsewhere, as rossen managed to get the code to work.
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