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Task/Bulls-and-cows/Nim/bulls-and-cows.nim

@@ -0,0 +1,35 @@
+import random, strutils, rdstdin
+randomize()
+
+proc random(a: string): char = a[random(0..a.len)]
+
+const
+  digits = "123456789"
+  size = 4
+
+var digitsSet: set[char] = {}
+for d in digits: digitsSet.incl d
+
+var chosen = newString(size)
+for i in 0..chosen.high: chosen[i] = random(digits)
+
+echo """I have chosen a number from $# unique digits from 1 to 9 arranged in a random order.
+You need to input a $# digit, unique digit number as a guess at what I have chosen""".format(size, size)
+
+var guesses = 0
+while true:
+  inc guesses
+  var guess = ""
+  while true:
+    guess = readLineFromStdin("\nNext guess [$#]: ".format(guesses)).strip()
+    if guess.len == size and allCharsInSet(guess, digitsSet):
+      break
+    echo "Problem, try again. You need to enter $# unique digits from 1 to 9".format(size)
+  if guess == chosen:
+    echo "\nCongratulations you guessed correctly in ",guesses," attempts"
+    break
+  var bulls, cows = 0
+  for i in 0 .. <size:
+    if guess[i] == chosen[i]: inc bulls
+    if guess[i] in chosen: inc cows
+  echo "  $# Bulls\n  $# Cows".format(bulls, cows)