Microsoft Interview Question Software Engineers
Country: United States
Interview Type: In-Person
Pseudo code:
Init CountCards = [] all zero
for each card in poker_hand:
CountCards[card] ++
Sort CountCards array descreasingly.
if CountCards[0] ==4: return "four of a kind"
if CountCards[0] ==3 and CountCards[1] ==2: return "full house"
if CountCards[0] ==3: return "three of a kind"
if CountCards[0] ==2 and CountCards[1] ==2: return "two pair"
if CountCards[0] ==2: return "one pair"
return "Nothing"
I've only been programming for about 2 weeks. So here is what I did. Any advice would be helpful. :-D
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace Poker
{
class Program
{
static string HandOutcome(List<int> hand)
{
Dictionary<int, int> tmp = new Dictionary<int, int>();
List<string> found = new List<string>();
foreach (int i in hand)
{
if (!tmp.ContainsKey(i))
{
tmp.Add(i, 1);
}
else
{
int curValue = tmp[i] + 1;
tmp[i] = curValue;
}
}
foreach (int i in tmp.Values)
{
if (i == 4)
{
found.Add("four");
}
else if (i == 3){
found.Add("three");
}else if (i == 2)
{
found.Add("pair");
}
}
if (found.Contains("four"))
{
return "You have a 4 of a kind...";
}
else if (found.Contains("three") && found.Contains("pair"))
{
return "You have a full house";
}else if (found.Contains("three")) {
return "You have 3 of a kind";
}
else if (found.Contains("pair")){
found.Remove("pair");
if (found.Contains("pair"))
{
return "You have 2 pair!";
}
else
{
return "You have a pair..";
}
}
else
{
return "You have nothing...";
}
}
static void Main(string[] args)
{
List<int> myHand = new List<int>();
myHand.Add(2);
myHand.Add(2);
myHand.Add(3);
myHand.Add(3);
myHand.Add(3);
string result = HandOutcome(myHand);
MessageBox.Show(result);
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace Poker
{
class Program
{
static string HandOutcome(List<int> hand)
{
Dictionary<int, int> tmp = new Dictionary<int, int>();
List<string> found = new List<string>();
foreach (int i in hand)
{
if (!tmp.ContainsKey(i))
{
tmp.Add(i, 1);
}
else
{
int curValue = tmp[i] + 1;
tmp[i] = curValue;
}
}
foreach (int i in tmp.Values)
{
if (i == 4)
{
found.Add("four");
}
else if (i == 3){
found.Add("three");
}else if (i == 2)
{
found.Add("pair");
}
}
if (found.Contains("four"))
{
return "You have a 4 of a kind...";
}
else if (found.Contains("three") && found.Contains("pair"))
{
return "You have a full house";
}else if (found.Contains("three")) {
return "You have 3 of a kind";
}
else if (found.Contains("pair")){
found.Remove("pair");
if (found.Contains("pair"))
{
return "You have 2 pair!";
}
else
{
return "You have a pair..";
}
}
else
{
return "You have nothing...";
}
}
static void Main(string[] args)
{
List<int> myHand = new List<int>();
myHand.Add(2);
myHand.Add(2);
myHand.Add(3);
myHand.Add(3);
myHand.Add(3);
string result = HandOutcome(myHand);
MessageBox.Show(result);
}
}
}
namespace Poker
{
class Program
{
static string HandOutcome(List<int> hand)
{
Dictionary<int, int> tmp = new Dictionary<int, int>();
List<string> found = new List<string>();
foreach (int i in hand)
{
if (!tmp.ContainsKey(i))
{
tmp.Add(i, 1);
}
else
{
int curValue = tmp[i] + 1;
tmp[i] = curValue;
}
}
foreach (int i in tmp.Values)
{
if (i == 4)
{
found.Add("four");
}
else if (i == 3){
found.Add("three");
}else if (i == 2)
{
found.Add("pair");
}
}
if (found.Contains("four"))
{
return "You have a 4 of a kind...";
}
else if (found.Contains("three") && found.Contains("pair"))
{
return "You have a full house";
}else if (found.Contains("three")) {
return "You have 3 of a kind";
}
else if (found.Contains("pair")){
found.Remove("pair");
if (found.Contains("pair"))
{
return "You have 2 pair!";
}
else
{
return "You have a pair..";
}
}
else
{
return "You have nothing...";
}
}
static void Main(string[] args)
{
List<int> myHand = new List<int>();
myHand.Add(2);
myHand.Add(2);
myHand.Add(3);
myHand.Add(3);
myHand.Add(3);
string result = HandOutcome(myHand);
MessageBox.Show(result);
}
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace Poker
{
class Program
{
static string HandOutcome(List<int> hand)
{
Dictionary<int, int> tmp = new Dictionary<int, int>();
List<string> found = new List<string>();
foreach (int i in hand)
{
if (!tmp.ContainsKey(i))
{
tmp.Add(i, 1);
}
else
{
int curValue = tmp[i] + 1;
tmp[i] = curValue;
}
}
foreach (int i in tmp.Values)
{
if (i == 4)
{
found.Add("four");
}
else if (i == 3){
found.Add("three");
}else if (i == 2)
{
found.Add("pair");
}
}
if (found.Contains("four"))
{
return "You have a 4 of a kind...";
}
else if (found.Contains("three") && found.Contains("pair"))
{
return "You have a full house";
}else if (found.Contains("three")) {
return "You have 3 of a kind";
}
else if (found.Contains("pair")){
found.Remove("pair");
if (found.Contains("pair"))
{
return "You have 2 pair!";
}
else
{
return "You have a pair..";
}
}
else
{
return "You have nothing...";
}
}
static void Main(string[] args)
{
List<int> myHand = new List<int>();
myHand.Add(2);
myHand.Add(2);
myHand.Add(3);
myHand.Add(3);
myHand.Add(3);
string result = HandOutcome(myHand);
MessageBox.Show(result);
}
}
}
Works but I've only been programming for a little over a week so any advice would be helpful. :-)
static string HandOutcome(List<int> hand)
{
Dictionary<int, int> tmp = new Dictionary<int, int>();
List<string> found = new List<string>();
foreach (int i in hand)
{
if (!tmp.ContainsKey(i))
{
tmp.Add(i, 1);
}
else
{
int curValue = tmp[i] + 1;
tmp[i] = curValue;
}
}
foreach (int i in tmp.Values)
{
if (i == 4)
{
found.Add("four");
}
else if (i == 3){
found.Add("three");
}else if (i == 2)
{
found.Add("pair");
}
}
if (found.Contains("four"))
{
return "You have a 4 of a kind...";
}
else if (found.Contains("three") && found.Contains("pair"))
{
return "You have a full house";
}else if (found.Contains("three")) {
return "You have 3 of a kind";
}
else if (found.Contains("pair")){
found.Remove("pair");
if (found.Contains("pair"))
{
return "You have 2 pair!";
}
else
{
return "You have a pair..";
}
}
else
{
return "You have nothing...";
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
namespace ConsoleApplication46
{
class Program
{
static void Main(string[] args)
{
// get hand
string[] input_data = File.ReadAllText(@"G:\input.txt").Split(new char[] { ' ','\n','\r','\t'},StringSplitOptions.RemoveEmptyEntries);
Dictionary<int, int> result = new Dictionary<int, int>();
// count the same cards
for (int i = 0; i<input_data.Length;i++)
{
var key = int.Parse(input_data[i]);
if (result.ContainsKey(key))
{
result[key]++;
}
else
{
result.Add(key,1);
}
}
// begin from the most expensive combination
if (result.ContainsValue(4))
{
Console.WriteLine("four of a kind");
}
else if (result.ContainsValue(3) && result.ContainsValue(2))
{
Console.WriteLine("full house");
}
else if (result.ContainsValue(3))
{
Console.WriteLine("three of a kind");
}
else if(result.ContainsValue(2))
{
int count_pair=0;
foreach (KeyValuePair<int, int> item in result)
{
if (item.Value == 2)
{
count_pair++;
}
}
if (count_pair == 2)
{
Console.WriteLine("dable pair");
}
else
{
Console.WriteLine("pair");
}
}
Console.ReadKey();
}
}
}
Executes in O(n).
Public enum
{
None, OnePair, TwoPair, Triple, FullHouse, Quads
} Hands;
Hands GetPokerScore(int[] cards)
{
HashTable<int, int> cardCount = new HashTable<int, int>();
int pairCount = 0;
bool triple;
foreach(int i in cards)
{
int count = 1;
if(cardCount.Contains(i))
count = cardCount(i) + 1;
switch(count)
{
Case(4):
return Hands.Quads;
Case(3):
pairCount--;
triple = true;
break;
Case(2):
pairCount++;
break;
}
if(pairCount > 0 && triple)
return Hands.FullHouse;
cardCount.put(count);
}
if(paircount == 2)
Return Hands.TwoPair;
else if pairCount == 1
Return Hands.OnePair;
return Hands.None;
}
Does it in one traversal
Public enum
{
None, OnePair, TwoPair, Triple, FullHouse, Quads
} Hands;
Hands GetPokerScore(int[] cards)
{
HashTable<int, int> cardCount = new HashTable<int, int>();
int pairCount = 0;
bool triple;
foreach(int i in cards)
{
int count = 1;
if(cardCount.Contains(i))
count = cardCount(i) + 1;
switch(count)
{
Case(4):
return Hands.Quads;
Case(3):
pairCount--;
triple = true;
break;
Case(2):
pairCount++;
break;
}
if(pairCount > 0 && triple)
return Hands.FullHouse;
cardCount.put(count);
}
if(paircount == 2)
Return Hands.TwoPair;
else if pairCount == 1
Return Hands.OnePair;
return Hands.None;
}
public class PokerHands {
public void validPokerHand(int[] arr) {
TreeMap<Integer, Integer> hmap = new TreeMap<Integer, Integer>();
ArrayList<String> hands = new ArrayList<String>();
int count = 0;
for (int i = 0; i < arr.length; i++) {
if (hmap.containsKey(arr[i])) {
hmap.put(arr[i], hmap.get(arr[i]) + 1);
} else {
hmap.put(arr[i], 1);
}
}
if (hmap.size() == 5)
System.out.println("Poker Hand : All Different Cards");
else if (hmap.size() == 4)
System.out.println("Poker Hand : One Pair");
else {
if (hmap.size() == 3) {
if (hmap.containsValue(3))
System.out.println("Poker Hand : Three of a kind");
else
System.out.println("Poker Hand : Two Pairs");
} else if (hmap.size() == 2) {
if (hmap.containsValue(4))
System.out.println("Poker Hand : Four of a kind");
else
System.out.println("Poker Hand : Full House");
}
}
}
public static void main(String[] args) {
int[] arr = { 5, 3, 3, 3, 3 };
PokerHands ph = new PokerHands();
ph.validPokerHand(arr);
}
Without even checking the rest of the answers mine look pretty similar to one of them. This is the code.
public static void PokerHand() {
// Given an array of five integers that represents a poker hand e.g. {2,2,2,3,3}
// return the value of the hand, valid values are only "pair", "two pair",
// "three of a kind", "full house", "foud of a kind"
int[] cards = { 1, 1, 1, 9, 1 };
Dictionary<int, int> hashTable = new Dictionary<int, int>();
// Sort cards to start
Array.Sort(cards);
for(int i=0;i<cards.Length;i++) {
if(hashTable.ContainsKey(cards[i])) {
hashTable[cards[i]]++;
}
else {
hashTable.Add(cards[i], 1);
}
}
// I could obtain a dictionary of ocurrences. Get the values and remove the 1's
var validCards = hashTable.Values.Where(x => x > 1).ToArray();
Array.Sort(validCards);
// Valid hands are:
// 2 | 2,2 | 3 | 3,2 || 4
string hand_result = "";
if(validCards.Length == 0) {
hand_result = "Nothing!";
}
else if(validCards.Length == 1) {
switch (validCards[0])
{
case 2:
hand_result = "Pair";
break;
case 3:
hand_result = "Three of a kind";
break;
case 4:
hand_result = "Four of a kind";
break;
case 5:
hand_result = "Poker";
break;
}
}
else {
if(validCards[1] == 2) {
hand_result = "Two pairs";
}
else {
hand_result = "Full house";
}
}
Console.WriteLine("The hand is {0}", hand_result);
}
You have to take into account that a pair of 3's is better than a pair of 2's and so on.
You have to think of way to take into account each card count and each card value for each count. Just like so:
def valueOfHand(hand):
count = [0] * 13
for card in hand:
count[card-1] += 1
value = 0
for card in range(13):
if count[card] > 0:
value += (card + 1) * 100 ** count[card] # 100 for the numbers not overlap with the other indexes
return value
# count
# 4 3 2 1 0
valueOfHand([1, 1, 2, 2, 2]) # 2010000 -> 0002010000 -> 00 02 01 00 00
valueOfHand([13, 13, 13, 12, 12]) # 13120000 -> 0013120000 -> 00 13 12 00 00
valueOfHand([1, 1, 1, 1, 2]) # 100000200 -> 0100000200 -> 01 00 00 02 00
Pseudo code:
- I_forgot_C++ December 16, 2015