bool straight(vector<Card> cards)
{
  // check for flush
  int d, h, c, s;
  d=h=c=s=0;
  for(int i = 0; i < cards.size(); ++i)
    {
      if( cards.at(i).getSuit() == 0)
        ++d;
      if( cards.at(i).getSuit() == 1)
        ++h;
      if( cards.at(i).getSuit() == 2)
        ++c;
      if( cards.at(i).getSuit() == 3)
        ++s;
    }
  if( d>4 || h>4 || c>4 || s>4 )
    return false;

  // sort cards for straight algorithm
  sort(cards.begin(),cards.end());

  // create vector of duplicate cards
  vector<Card> tempCards;
  for (int i = 0; i < cards.size()-1; ++i)
    {
      if( cards.at(i).getRank() == cards.at(i+1).getRank()  )
        {
          tempCards.push_back(cards.at(i));
          cards.erase(cards.begin()+i);
        }
    }

  // if hand size < 5 exit
  if ( cards.size() < 5 )
    return false;

  // we know cards.size() is 5, 6, or 7
  // so, we need to run 1, 2, or 3 tests
  // testing if f(x)+1 = f(x+1)
  int k = cards.size() - 4;

  for (int j = 0; j < k; ++j)
    {
      int count = 0;
      int i = j;
      while ( (cards.at(i).getRank() + 1)  == cards.at(i+1).getRank() )
        {
          ++count;
          ++i;
          if( count > 3 )
            {
              return true;
            }
          if ( i == (4 + j) )
            break;
        }
    }

  // must check for Wheel Straight
  for(int i = 0; i < cards.size(); ++i)
    {
      if( cards.at(i).getRank() == 12 )
        {
          if( cards.at(0).getRank() == 0 &&
              cards.at(1).getRank() == 1 &&
              cards.at(2).getRank() == 2 &&
              cards.at(3).getRank() == 3 )
            {
              return true;
            }
          else
            return false;
        }
    }

  return false;
}

int main ()
{
  Deck deck;
  vector<Card> hand;
  double COUNT = 0;

  for ( int j=0; j<1000001; ++j)
    {
      deck.newDeck();
      deck.shuffleDeck();


      for(int i = 0; i<7; ++i)
        hand.push_back(deck.dealCard());

      if ( straight(hand) )
        {
          COUNT++;
        }
      hand.clear();
    }
  cout << endl << endl;
  cout << "Probability to make straight is 4.62%\n";
  cout << "Test Results: " << (double)COUNT/1000001 * 100 
         << "%" << endl;

  return 0;
}

Probability to make straight is 4.62%
Test Results: 4.595%
# ./main


Probability to make straight is 4.62%
Test Results: 4.6062%
# ./main


Probability to make straight is 4.62%
Test Results: 4.5984%
# ./main


Probability to make straight is 4.62%
Test Results: 4.6322%