Bulls and Cows


Task

Create a four digit random number from the digits   1   to   9,   without duplication.

The program should:

   ask for guesses to this number
   reject guesses that are malformed
   print the score for the guess


The score is computed as:

 The player wins if the guess is the same as the randomly chosen number, and the program ends.
 A score of one bull is accumulated for each digit in the guess that equals the corresponding digit in the randomly chosen initial number.
 A score of one cow is accumulated for each digit in the guess that also appears in the randomly chosen number, but in the wrong position.


Related tasks

   Bulls and cows/Player
   Guess the number
   Guess the number/With Feedback
   Mastermind


<?php
$size = 4;
 
$chosen = implode(array_rand(array_flip(range(1,9)), $size));
 
echo "I've chosen a number from $size unique digits from 1 to 9; you need
to input $size unique digits to guess my number\n";
 
for ($guesses = 1; ; $guesses++) {
    while (true) {
        echo "\nNext guess [$guesses]: ";
        $guess = rtrim(fgets(STDIN));
        if (!checkguess($guess))
            echo "$size digits, no repetition, no 0... retry\n";
        else
            break;
    }
    if ($guess == $chosen) {
        echo "You did it in $guesses attempts!\n";
        break;
    } else {
        $bulls = 0;
        $cows = 0;
        foreach (range(0, $size-1) as $i) {
            if ($guess[$i] == $chosen[$i])
                $bulls++;
            else if (strpos($chosen, $guess[$i]) !== FALSE)
                $cows++;
        }
        echo "$cows cows, $bulls bulls\n";
    }
}
 
function checkguess($g)
{
  global $size;
  return count(array_unique(str_split($g))) == $size &&
    preg_match("/^[1-9]{{$size}}$/", $g);
}
?>