void extend(char *s, int len, int i, int j, int *lo, int *hi)
{
	while(i >= 0 && i < len && s[i] == s[j]) {
		i--;
		j++;
	}

	if(j - i > *hi - *lo) {
		*lo = i;
		*hi = j;
	}
}

char* longestPalindrome(char* s) {
	int *lo, *hi;
	int len = strlen(s);

	lo = malloc(sizeof(int));
	hi = malloc(sizeof(int));

	*lo = *hi = 0;
	if(len < 2)
		return s;

	for(int i = 0; i < len - 1; i++) {
		extend(s, len, i, i, lo, hi);
		extend(s, len, i, i + 1, lo, hi);
	}

	*(s + (*hi)) = '\0';
	return s + *lo + 1;
}