SIGSEGV on codechef

[thmm]

When I run the following code it works fine on my Windows PC under Code::Blocks 17.12, but I get a SIGSEGV on codechef. What's wrong

#include <iostream>
#include <string>

using namespace std;

inline bool contains(const char *haystack)
{
  int cnt_c = 0, cnt_e = 0, cnt_f = 0, cnt_h = 0;

  for (size_t i = 0; i < 4; ++i)
  {
    switch (haystack[i])
    {
      case 'c': cnt_c++; break;
      case 'e': cnt_e++; break;
      case 'f': cnt_f++; break;
      case 'h': cnt_h++; break;
      default: return false;
    }
  }
  return cnt_c == 1 && cnt_e == 1 && cnt_f == 1 && cnt_h == 1;

}


int main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  int num_tests;
  cin >> num_tests;
  cin.ignore(255, '\n');
  string input;
  input.reserve(500000);

  while(num_tests--)
  {
    cin >> input;
    size_t size = input.size(), count = 0;
    for (size_t i = 0; i < size - 3; ++i)
    {
      if (contains(&input[i]))
      {
         ++count;
      }
    }
    if (count)
    {
      cout << "Lovely " << count << endl;
    }
    else
    {
      cout << "Normal" << endl;
    }
  }
}

The task it at https://www.codechef.com/problems/CHEFCHR#

[kbw]

What are your inputs? If the length is less than 3 characters, you're in trouble.

[thmm]

Thanks, I added the check for the size and it solved the SIGSEGV problem.