How to decide which hand is the strongest?

I actually coded something like this for some-one else a while back except that I had only 5 cards to play with instead of 7.

I've therefore had to change the logic quite a bit so I'd test it thoroughly if you want to use it:

using System;

using System.Collections.Generic;

using System.Linq;

struct Card

{

static string values = "AKQJT98765432";

static string suits = "shdc";

public readonly int Value;

public readonly int Suit;

public Card(int value, int suit)

{

Value = value;

Suit = suit;

}

public override string ToString()

{

return String.Format("{0}{1}", values[Value], suits[Suit]);

}

class CardValueComparer : IEqualityComparer

{

public bool Equals(Card c1, Card c2)

{

return c1.Value == c2.Value;

}

public int GetHashCode(Card c)

{

return c.Value.GetHashCode();

}

class Program

{

static string[] names1 = {"Ace", "King", "Queen", "Jack", "Ten", "Nine", "Eight", "Seven",

"Six", "Five", "Four", "Three", "Two"};

static string[] names2 = {"Aces", "Kings", "Queens", "Jacks", "Tens", "Nines", "Eights", "Sevens", "Sixes", "Fives", "Fours", "Threes", "Twos"};

static string[] suits = {"Spades", "Hearts", "Diamonds", "Clubs"};

static Card[] cards = new Card[7];

static Random rand = new Random();

static void Main()

{

string yn;

while(true)

{

Deal();

AssessHand();

{

Console.Write("Another deal y/n : ");

yn = Console.ReadLine().ToLower();

}

while(yn != "y" && yn != "n");

if (yn == "n") return;

Console.WriteLine();

}

static void Deal()

{

int value, suit;

bool alreadyDrawn;

int count = 0;

while(count < 7)

{

value = rand.Next(13);

suit = rand.Next(4);

alreadyDrawn = false;

for(int i = 0; i < count; i++)

{

if (cards[i].Value == value && cards[i].Suit == suit)

{

alreadyDrawn = true;

break;

}

if (!alreadyDrawn)

{

cards[count] = new Card(value, suit);

count++;

}

Console.Write ("Cards as dealt : ");

foreach(Card c in cards) Console.Write("{0} ", c);

Console.WriteLine();

}

static void AssessHand()

{

// sort by multiple

var groupings = from card in cards group card by card.Value into g

orderby g.Count() descending, g.Key select g;

Console.Write ("Sorted by multiple : ");

foreach(var g in groupings)

{

foreach (Card c in g) Console.Write("{0} ", c);

}

Console.WriteLine();

int handType = -1;

string hand = null;

// check for card multiples

int count1 = groupings.First().Count();

int count2 = groupings.ElementAt(1).Count();

int value1 = groupings.First().Key;

int value2 = groupings.ElementAt(1).Key;

if (count1 == 4)

{

handType = 1;

hand = "Four " + names2[value1];

}

else if (count1 == 3 && count2 >= 2)

{

handType = 2;

hand = "Full House - " + names2[value1] + " and " + names2[value2];

}

else if (count1 == 3)

{

handType = 5;

hand = "Three " + names2[value1];

}

else if (count1 == 2 && count2 == 2)

{

handType = 6;

hand = "Two Pairs - " + names2[value1] + " and " + names2[value2];

}

else if (count1 == 2)

{

handType = 7;

hand = "Pair of " + names2[value1];

}

else

{

handType = 8;

hand = names1[value1] + " high";

}

// sort by value

cards = (from card in cards orderby card.Value select card).ToArray();

Console.Write ("Sorted by value : ");

foreach(Card card in cards) Console.Write("{0} ", card);

Console.WriteLine();

// now check for straight

Card[] distinctCards = cards.Distinct(new CardValueComparer()).ToArray(); // remove cards with duplicate values

bool straight = false;

if (distinctCards.Length >= 5)

{

for(int i = 0; i < distinctCards.Length - 4; i++)

{

if (distinctCards[i].Value == distinctCards[i + 4].Value - 4)

{

if (handType > 4)

{

hand = names1[distinctCards[i].Value] + "-high Straight";

handType = 4;

}

straight = true;

break;

}

// sort by suit

groupings = from card in cards group card by card.Suit into g

orderby g.Count() descending select g;

Console.Write ("Sorted by suit : ");

foreach(var g in groupings)

{

foreach (Card c in g) Console.Write("{0} ", c);

}

Console.WriteLine();

// now check for flush

int count = groupings.First().Count();

if (count >= 5)

{

int index = groupings.First().First().Value;

int suit = groupings.First().Key;

if (handType > 3)

{

handType = 3;

hand = names1[index] + "-high Flush in " + suits[suit];

}

if (straight)

{

// now check for straight flush

Card[] flushCards = (from card in groupings.First() orderby card.Value select card).ToArray();

for(int i = 0; i < count - 4; i++)

{

if (flushCards[i].Value == flushCards[i + 4].Value - 4)

{

bool straightFlush = true;

int flushSuit = flushCards[i].Suit;

for(int j = i + 1; j < i + 5; j++)

{

if (flushSuit != flushCards[j].Suit)

{

straightFlush = false;

break;

}

if (straightFlush)

{

handType = 0;

hand = names1[flushCards[i].Value] + "-high Straight Flush in " + suits[flushCards[i].Suit];

break;

}

Console.Write ("Strongest hand : ");

Console.WriteLine(hand);

}

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Suthish Nair14y ago
Hat's off Vulpes! One vote for your reply....
Vulpes14y ago
I actually coded something like this for some-one else a while back except that I had only 5 cards to play with instead of 7.

I've therefore had to change the logic quite a bit so I'd test it thoroughly if you want to use it:

using System;
using System.Collections.Generic;
using System.Linq;

struct Card
{
static string values = "AKQJT98765432";
static string suits = "shdc";

public readonly int Value;
public readonly int Suit;

public Card(int value, int suit)
{
Value = value;
Suit = suit;
}

public override string ToString()
{
return String.Format("{0}{1}", values[Value], suits[Suit]);
}
}

class CardValueComparer : IEqualityComparer
{
public bool Equals(Card c1, Card c2)
{
return c1.Value == c2.Value;
}

public int GetHashCode(Card c)
{
return c.Value.GetHashCode();
}
}

class Program
{
static string[] names1 = {"Ace", "King", "Queen", "Jack", "Ten", "Nine", "Eight", "Seven",
"Six", "Five", "Four", "Three", "Two"};

static string[] names2 = {"Aces", "Kings", "Queens", "Jacks", "Tens", "Nines", "Eights", "Sevens", "Sixes", "Fives", "Fours", "Threes", "Twos"};

static string[] suits = {"Spades", "Hearts", "Diamonds", "Clubs"};

static Card[] cards = new Card[7];
static Random rand = new Random();

static void Main()
{
string yn;

while(true)
{
Deal();
AssessHand();

do
{
Console.Write("Another deal y/n : ");
yn = Console.ReadLine().ToLower();
}
while(yn != "y" && yn != "n");

if (yn == "n") return;
Console.WriteLine();
}
}

static void Deal()
{
int value, suit;
bool alreadyDrawn;
int count = 0;

while(count < 7)
{
value = rand.Next(13);
suit = rand.Next(4);
alreadyDrawn = false;

for(int i = 0; i < count; i++)
{
if (cards[i].Value == value && cards[i].Suit == suit)
{
alreadyDrawn = true;
break;
}
}

if (!alreadyDrawn)
{
cards[count] = new Card(value, suit);
count++;
}
}

Console.Write ("Cards as dealt : ");
foreach(Card c in cards) Console.Write("{0} ", c);
Console.WriteLine();
}

static void AssessHand()
{
// sort by multiple

var groupings = from card in cards group card by card.Value into g
orderby g.Count() descending, g.Key select g;

Console.Write ("Sorted by multiple : ");

foreach(var g in groupings)
{
foreach (Card c in g) Console.Write("{0} ", c);
}

Console.WriteLine();

int handType = -1;
string hand = null;

// check for card multiples

int count1 = groupings.First().Count();
int count2 = groupings.ElementAt(1).Count();
int value1 = groupings.First().Key;
int value2 = groupings.ElementAt(1).Key;

if (count1 == 4)
{
handType = 1;
hand = "Four " + names2[value1];
}
else if (count1 == 3 && count2 >= 2)
{
handType = 2;
hand = "Full House - " + names2[value1] + " and " + names2[value2];
}
else if (count1 == 3)
{
handType = 5;
hand = "Three " + names2[value1];
}
else if (count1 == 2 && count2 == 2)
{
handType = 6;
hand = "Two Pairs - " + names2[value1] + " and " + names2[value2];
}
else if (count1 == 2)
{
handType = 7;
hand = "Pair of " + names2[value1];
}
else
{
handType = 8;
hand = names1[value1] + " high";
}

// sort by value
cards = (from card in cards orderby card.Value select card).ToArray();

Console.Write ("Sorted by value : ");
foreach(Card card in cards) Console.Write("{0} ", card);
Console.WriteLine();

// now check for straight

Card[] distinctCards = cards.Distinct(new CardValueComparer()).ToArray(); // remove cards with duplicate values

bool straight = false;

if (distinctCards.Length >= 5)
{
for(int i = 0; i < distinctCards.Length - 4; i++)
{
if (distinctCards[i].Value == distinctCards[i + 4].Value - 4)
{
if (handType > 4)
{
hand = names1[distinctCards[i].Value] + "-high Straight";
handType = 4;
}
straight = true;
break;
}
}
}

// sort by suit

groupings = from card in cards group card by card.Suit into g
orderby g.Count() descending select g;

Console.Write ("Sorted by suit : ");

foreach(var g in groupings)
{
foreach (Card c in g) Console.Write("{0} ", c);
}

Console.WriteLine();

// now check for flush
int count = groupings.First().Count();

if (count >= 5)
{
int index = groupings.First().First().Value;
int suit = groupings.First().Key;

if (handType > 3)
{
handType = 3;
hand = names1[index] + "-high Flush in " + suits[suit];
}

if (straight)
{
// now check for straight flush
Card[] flushCards = (from card in groupings.First() orderby card.Value select card).ToArray();

for(int i = 0; i < count - 4; i++)
{
if (flushCards[i].Value == flushCards[i + 4].Value - 4)
{
bool straightFlush = true;
int flushSuit = flushCards[i].Suit;

for(int j = i + 1; j < i + 5; j++)
{
if (flushSuit != flushCards[j].Suit)
{
straightFlush = false;
break;
}
}

if (straightFlush)
{
handType = 0;
hand = names1[flushCards[i].Value] + "-high Straight Flush in " + suits[flushCards[i].Suit];
break;
}
}
}
}
}

Console.Write ("Strongest hand : ");
Console.WriteLine(hand);
}
}