Author:

• Name: Leonid A. Broukhis
  Location: US - United States of America (United States)

To build:

    make all

To use:

To have the computer guess:

    ./leo [colors]

To guess the computer’s number:

    ./mind [colors]

where:

[colors] is the number of possible colors (1 to 15) (default: 6)

Judges’ remarks:

By default, the number of colors is 6. You may specify a value of between 1 and 15 colors. See the author’s notes for instructions of how to play.

We look forward to more entries from the newer members of the International Internet community.

Author’s remarks:

This program plays Mastermind, if you call it by a name ending by d, otherwise it solves Mastermind. Call it without parameters to use 6 digits (colors), or indicate the number of possible digits (you cannot change the number of positions so easily).

The number in parentheses is the number of possible combinations, based on previous questions and answers. If you solve the puzzle, “(1)” indicates that your previous moves are enough to give correct answer. If the program acts as solver and terminates prematurely, it means that you’re mistaken in your answers to its question(s). Question marks indicate the number of digits you have to enter (either 4 when you guess or 2 when computer guesses).

Note that the program uses the same code for both player and solver, and the only place where it makes a difference is the interactive part. Many obfuscations have been made to achieve this. An expression giving (bulls * 16 + cows) from two numbers is, however, quite straightforward :-) , as well as the arithmetic of binary coded colors-base numbers is.

Limitations: maximum number of digits (colors) is 14 (1..F).

Suggestions: Use terminal (or emulator) with non-destructive backspaces. Do “disable scrolling” on cmdtool or similar emulators.

Bugs

Please don’t type ^D at the prompt!!

EXAMPLE: Suppose we think of 1234

    $ ./leo
    (1296): 6433
    ?? 12               # one 3 is a bull, another is a cow, and 4 is a cow
    (160): 5363
    ?? 02               # both 3's are cows
    (21): 4231
    ?? 22               # 2 and 3 are bulls, 4 and 1 are cows
    (2): 4132
    ?? 13               # 3 is a bull; 1, 2 and 4 are cows
    (1): 1234
    ?? 40               # you may enter everything there

EXAMPLE: Guess the computer’s number

    $ ./mind
    (1296): ???? 1122   # my strategy isn't the best, just as example
    00
    (256): ???? 3344
    20
    (18): ???? 5566
    02
    (6): ???? 3654
    11
    (2): ???? 3355
    00
    (1): ???? 6444
    40                  # we have guessed the number

Primary files

• leo.c - entry source code
• Makefile - entry Makefile
• leo.orig.c - original source code

Secondary files

• 1993_leo.tar.bz2 - download entry tarball
• README.md - markdown source for this web page
• .entry.json - entry summary and manifest in JSON
• .gitignore - list of files that should not be committed under git
• .path - directory path from top level directory
• index.html - this web page

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