Given a string find the largest substring which is palindrome

Problem:
Given a string find the largest substring which is palindrome.

Solution:
Test if a substring is a palindrome starting from its potential "center":

int longestPalindromicSubstring(char* str)
{
 int len = strlen(str);
 int maxLength = 1;
 int start = 0;
 int low, high;
 
 for(int i = 1; i < len; i++)
 {
  // Find longest even length palindrome with
  // center points as i-1 and i
  low = i-1;
  high = i;
  while(low >= 0 && high < len && str[low] == str[high])
  {
   if(high - low + 1 > maxLength)
   {
    start = low;
    maxLength = high - low + 1;
   }
   low--;
   high++;
  }
  
  // Find longest odd length palindrom with
  // center point as i
  low = i-1;
  high = i+1;
  while(low >= 0 && high < len && str[low] == str[high])
  {
   if(high - low + 1 > maxLength)
   {
    start = low;
    maxLength = high - low + 1;
   }
   low--;
   high++;
  }
 }
 
 printf("Longest Palindromic Substring is: ");
 for(int i = start; i <= start + maxLength - 1; i++)
 {
  printf("%c", str[i]);
 }
 
 return maxLength;
}

Complexity:

time - O(n^2)
space - O(1)

Links and credits:
http://www.careercup.com/question?id=20351666
O(n) algorithm (Manacher's Algorithm) is discussed at http://discuss.leetcode.com/questions/178/longest-palindromic-substring