to find if a given string is palindrome or is not palindrome

Question

I made a program to find if a entered string is palindrome or not palindrome but it always says that its not a palindrome

#include  
#include          


        

Answer 1

Here's a shorter solution (C++; identical line count for C):

bool is_p(char const * const str, ptrdiff_t n)
{
  if (n < 1) return false;

  auto p = str, q = str + n - 1;
  while (*(p++) == *(q--))
    if (p >= q)
      return true;
  return false;
}

Answer 2

You can also use STL to check if a given string is palindrome using function equal. Lets say you have an std::string named x, then the following function call determines if x is palindrome

equal(x.begin(), x.begin() + x.size() / 2, x.rbegin());

Answer 3

Your central comparison is flawed:

if (str[i] != str[i+halflen]) 

This isn't comparing the two characters you think it is.

Try entering "HelloHello" into your program, it will say it is a palindrome!

You need to compare these two:

if (str[i] != str[len-i-1])

(and fix the braces, as suggested in the other answer)