Data commit

Task/Bulls-and-cows-Player/C-sharp/bulls-and-cows-player.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BullsAndCows
+{
+    class Program
+    {
+        const int ANSWER_SIZE = 4;
+
+        static IEnumerable<string> Permutations(int size)
+        {
+            if (size > 0)
+            {
+                foreach (string s in Permutations(size - 1))
+                    foreach (char n in "123456789")
+                        if (!s.Contains(n))
+                            yield return s + n;
+            }
+            else
+                yield return "";
+        }
+
+        static IEnumerable<T> Shuffle<T>(IEnumerable<T> source)
+        {
+            Random random = new Random();
+            List<T> list = source.ToList();
+            while (list.Count > 0)
+            {
+                int ix = random.Next(list.Count);
+                yield return list[ix];
+                list.RemoveAt(ix);
+            }
+        }
+
+        static bool ReadBullsCows(out int bulls, out int cows)
+        {
+            string[] input = Console.ReadLine().Split(',').ToArray();
+            bulls = cows = 0;
+            if (input.Length < 2)
+                return false;
+            else
+                return int.TryParse(input[0], out bulls)
+                    && int.TryParse(input[1], out cows);
+        }
+
+        static void Main(string[] args)
+        {
+            Console.WriteLine("Bulls and Cows");
+            Console.WriteLine("==============");
+            Console.WriteLine();
+            List<string> answers = Shuffle(Permutations(ANSWER_SIZE)).ToList();
+            while (answers.Count > 1)
+            {
+                string guess = answers[0];
+                Console.Write("My guess is {0}. How many bulls, cows? ", guess);
+                int bulls, cows;
+                if (!ReadBullsCows(out bulls, out cows))
+                    Console.WriteLine("Sorry, I didn't understand that. Please try again.");
+                else
+                    for (int ans = answers.Count - 1; ans >= 0; ans--)
+                    {
+                        int tb = 0, tc = 0;
+                        for (int ix = 0; ix < ANSWER_SIZE; ix++)
+                            if (answers[ans][ix] == guess[ix])
+                                tb++;
+                            else if (answers[ans].Contains(guess[ix]))
+                                tc++;
+                        if ((tb != bulls) || (tc != cows))
+                            answers.RemoveAt(ans);
+                    }
+            }
+            if (answers.Count == 1)
+                Console.WriteLine("Hooray! The answer is {0}!", answers[0]);
+            else
+                Console.WriteLine("No possible answer fits the scores you gave.");
+        }
+    }
+}