Exercise03_17.java

package ch_03;

import java.util.Random;
import java.util.Scanner;

/**
 * *3.17 (Game: scissor, rock, paper) Write a program that plays the popular
 * scissor-rock-paper game. (A scissor can cut a paper, a rock can knock a
 * scissor, and a paper can wrap a rock.)
 * <p>
 * The program randomly generates a number 0, 1, or 2 representing scissor,
 * rock, and paper. The program prompts the user to enter a number 0, 1, or 2
 * and displays a message indicating whether the user or the computer wins,
 * loses, or draws.
 * <p>
 * Here are sample runs: scissor (0), rock (1), paper (2): 1 The computer is
 * scissor. You are rock. You won
 *
 */
public class Exercise03_17 {

    public static void main(String[] args) {

        final int scissor = 0;
        final int rock = 1;
        final int paper = 2;

        Scanner in = new Scanner(System.in);
        Random random = new Random();

        System.out.println("Scissor (0), rock (1), paper (2): ");

        int user = in.nextInt();

        if (user == 0 || user == 1 || user == 2) {

            int comp = random.nextInt(3);
            String res = "The computer is";
            switch (user) {
                case 0:
                    if (comp == scissor) {
                        res += " scissor and you are scissor, it's a draw.";
                    } else if (comp == rock) {
                        res += " rock and you are scissor, you lost.";
                    } else if (comp == paper) {
                        res += " paper and you are scissor, you won.";
                    }
                    break;
                case 1:
                    if (comp == scissor) {
                        res += " scissor and you are rock, you won.";
                    } else if (comp == rock) {
                        res += " rock and you are rock, its a draw.";
                    } else if (comp == paper) {
                        res += " paper and you are rock, you lost.";
                    }
                    break;
                case 2:
                    if (comp == scissor) {
                        res += " scissor and you are paper, you lost.";
                    } else if (comp == rock) {
                        res += " rock and you are paper, you won.";
                    } else if (comp == paper) {
                        res += " paper and you are paper, it's a draw.";
                    }
                    break;

            }
            System.out.println(res);

        } else {
            System.out.println("Computer wins, you input an invalid value so you forfiet this round!");
        }

        in.close();
    }

}