bulls_and_cows.a60

b̲e̲g̲i̲n̲
    i̲n̲t̲e̲g̲e̲r̲ secret, count, guess, cows, bulls, i, j;
    r̲e̲a̲l̲ seed;

    i̲n̲t̲e̲g̲e̲r̲ p̲r̲o̲c̲e̲d̲u̲r̲e̲ digit(num, ps);
        v̲a̲l̲u̲e̲ num;
        i̲n̲t̲e̲g̲e̲r̲ num, ps;
    b̲e̲g̲i̲n̲
        num := num ÷ 10↑ps;
        digit := num - num ÷ 10 * 10
    e̲n̲d̲;

    B̲o̲o̲l̲e̲a̲n̲ p̲r̲o̲c̲e̲d̲u̲r̲e̲ malformed(num);
        v̲a̲l̲u̲e̲ num;
        i̲n̲t̲e̲g̲e̲r̲ num;
    b̲e̲g̲i̲n̲
        malformed := num > 9876 ∨ num < 0123 ∨
                     digit(num, 0) = digit(num, 1) ∨
                     digit(num, 0) = digit(num, 2) ∨
                     digit(num, 0) = digit(num, 3) ∨
                     digit(num, 1) = digit(num, 2) ∨
                     digit(num, 1) = digit(num, 3) ∨
                     digit(num, 2) = digit(num, 3);
    e̲n̲d̲;

    SETRANDOM(TIMEOFDAY);
    secret := 0;
    f̲o̲r̲ i := 0 w̲h̲i̲l̲e̲ malformed(secret) d̲o̲
        secret := entier(RANDOM * 9877);

    PRINTTEXT(`Welcome to bulls and cows!'); NLCR;
    NLCR;
    PRINTTEXT(`I choose a number made of 4 digits (from 0 to 9) without repetitions.'); NLCR;
    PRINTTEXT(`You enter a number of 4 digits, and I say you how many of them'); NLCR;
    PRINTTEXT(`are in my secret number but in wrong position (cows),'); NLCR;
    PRINTTEXT(`and how many are in the right position (bulls).'); NLCR;
    NLCR;

    count := 0;
    guess := 0;
    f̲o̲r̲ i := 0 w̲h̲i̲l̲e̲ guess ≠ secret d̲o̲ b̲e̲g̲i̲n̲
        count := count + 1;
again:
        PRINTTEXT(`Guess a number.');
        NLCR;
        guess := entier(read);
        i̲f̲ malformed(guess) t̲h̲e̲n̲
            g̲o̲t̲o̲ again;

        cows := 0;
        bulls := 0;

        f̲o̲r̲ i := 0 s̲t̲e̲p̲ 1 u̲n̲t̲i̲l̲ 3 d̲o̲
            f̲o̲r̲ j := 0 s̲t̲e̲p̲ 1 u̲n̲t̲i̲l̲ 3 d̲o̲
                i̲f̲ digit(secret, i) = digit(guess, j) t̲h̲e̲n̲
                    i̲f̲ i = j t̲h̲e̲n̲
                        bulls := bulls + 1
                    e̲l̲s̲e̲
                        cows := cows + 1;

        PRINTTEXT(`You scored ');
        print(bulls);
        PRINTTEXT(` bulls and ');
        print(cows);
        PRINTTEXT(` cows.');
        NLCR
    e̲n̲d̲;
    PRINTTEXT(`Correct. That took you ');
    print(count);
    PRINTTEXT(` guesses.')
    NLCR
e̲n̲d̲