janken.php

<?php
define("ROCK",0);
define("SCISSORS",1);
define("PAPER",2);
define("WIN","あなたの勝ちです\n");
define("LOSE","あなたの負けです\n");
define("DRAW","ひきわけです\n");

$janken = array(ROCK => "グー", SCISSORS => "チョキ", PAPER => "パー");

echo "じゃんけんしましょう\n";
echo "グーは ", ROCK, " , チョキは ", SCISSORS, " , パーは ", PAPER, " を入力してね\n";

$input = intval(fgets(STDIN,4096));
$randval = rand(0,2);

echo "あなたの手は{$janken[$input]}です\n";
echo "わたしの手は{$janken[$randval]}です\n";

switch($input) {
    case ROCK:
        switch($randval) {
            case ROCK:
                echo DRAW;
                break;
            case SCISSORS:
                echo WIN;
                break;
            case PAPER:
                echo LOSE;
                break;
        }
        break;
    case SCISSORS:
        switch($randval) {
            case ROCK:
                echo LOSE;
                break;
            case SCISSORS:
                echo DRAW;
                break;
            case PAPER:
                echo WIN;
                break;
        }
        break;
    case PAPER:
        switch($randval) {
            case ROCK:
                echo WIN;
                break;
            case SCISSORS:
                echo LOSE;
                break;
            case PAPER:
                echo DRAW;
                break;
        }
        break;
}

?>

janken.py

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import random

ROCK = 0
SCISSORS = 1
PAPER = 2
WIN = "あなたの勝ちです"
LOSE = "あなたの負けです"
DRAW = "引き分けです"

janken = {ROCK:"グー", SCISSORS:"チョキ", PAPER:"パー"}

print "じゃんけんしましょう"
print "グーは %s, チョキは %s, パーは %s を入力してね" % (ROCK, SCISSORS, PAPER)

inval = input()

randval = random.randint(0, 2)

print "あなたの手: %s" % (janken[inval])
print "わたしの手: %s" % (janken[randval])

if inval == ROCK:
    if randval == ROCK:
        print DRAW
    elif randval == SCISSORS:
        print WIN
    else:
        print LOSE
elif inval == SCISSORS:
    if randval == ROCK:
        print LOSE
    elif randval == SCISSORS:
        print DRAW
    else:
        print WIN
else:
    if randval == ROCK:
        print WIN
    elif randval == SCISSORS:
        print LOSE
    else:
        print DRAW

janken.rb

ROCK = 0
SCISSORS = 1
PAPER = 2
DRAW = "あいこですね"
WIN = "あなたの勝ちです"
LOSE = "残念、私の勝ちです"

janken = {
    ROCK      => "グー",
    SCISSORS  => "チョキ",
    PAPER     => "パー"
}

puts "じゃんけんしましょう"
puts "グーのときは #{ROCK}, チョキのときは #{SCISSORS}, パーのときは #{PAPER} を入力してね"

input = gets
input = input.to_i

randnum = rand(3)

puts "あなたが出した手: #{janken[input]}"
puts "わたしが出した手: #{janken[randnum]}"

case input
when ROCK
    case randnum
    when ROCK
        puts DRAW
    when SCISSORS
        puts WIN
    else
        puts LOSE
    end
when SCISSORS
    case randnum
    when ROCK
        puts LOSE
    when SCISSORS
        puts DRAW
    else
        puts WIN
    end
when PAPER
    case randnum
    when ROCK
        puts WIN
    when SCISSORS
        puts LOSE
    else
        puts DRAW
    end
end