palindrome problem

[ozair]

I wrote a function that takes an integer as a parameter and returns a Boolean variable stating that whether that number is a palindrome or not...

here is the code for the function..

bool IsPalindrome(int number)
{
int digits=0; int n=number;

bool equal=true;

for (int pwr=1; number/pwr>0; pwr=pwr*10)
digits=digits+1;

pwr=pwr/10;

for (int i=0; i<digits/2 && equal; i++)
{
if (number/pwr!=n%10)
equal=false;

n=n/10;
number=number%pwr;
pwr=pwr/10;
}

return equal;
}

Now it works for every number till having maximum 9 digits.. when I gave 1234554321 or 1111551111 (having 10 digits), the function returns false.. it should not!, I dont know what is going wrong...

I have check the range of the 'int' type variable, its from -2147483648 to 2147483647, the maximum number is of 10 digits and my inputs are within the range of the data type... I have no idea what is going wrong...

help me identify this error!

[Duthomhas]

The error is because your variable pwr is exceeding ten digits when you calculate the number of digits. BTW, you should not declare pwr in a loop.

Better to count the digits first, then initialize pwr.

Hope this helps.

[sunslayer]

i don't see the need for all the math, this is a simple example that returns bool t/f for chars/ints

bool IsPalindrome(char text[])
{
	int len=strlen(text)-1;
	for(int x = 0,y = len;x<(int)len/2;x++,y--)
		if(text[x]!=text[y])
			return 0;
	return 1;
}