2016 Update

Task/Bulls-and-cows/PowerShell/bulls-and-cows.psh

@@ -0,0 +1,47 @@
+[int]$guesses = $bulls = $cows = 0
+[string]$guess = "none"
+[string]$digits = ""
+
+while ($digits.Length -lt 4)
+{
+    $character = [char](49..57 | Get-Random)
+
+    if ($digits.IndexOf($character) -eq -1) {$digits += $character}
+}
+
+Write-Host "`nGuess four digits (1-9) using no digit twice.`n" -ForegroundColor Cyan
+
+while ($bulls -lt 4)
+{
+    do
+    {
+        $prompt = "Guesses={0:0#}, Last='{1,4}', Bulls={2}, Cows={3}; Enter your guess" -f $guesses, $guess, $bulls, $cows
+        $guess = Read-Host $prompt
+
+        if ($guess.Length -ne 4)                     {Write-Host "`nMust be a four-digit number`n" -ForegroundColor Red}
+        if ($guess -notmatch "[1-9][1-9][1-9][1-9]") {Write-Host "`nMust be numbers 1-9`n"         -ForegroundColor Red}
+    }
+    until ($guess.Length -eq 4)
+
+    $guesses += 1
+    $bulls = $cows = 0
+
+    for ($i = 0; $i -lt 4; $i++)
+    {
+        $character = $digits.Substring($i,1)
+
+        if ($guess.Substring($i,1) -eq $character)
+        {
+            $bulls += 1
+        }
+        else
+        {
+            if ($guess.IndexOf($character) -ge 0)
+            {
+                $cows += 1
+            }
+        }
+    }
+}
+
+Write-Host "`nYou won after $($guesses - 1) guesses." -ForegroundColor Cyan