RosettaCodeData/Task/Rock-paper-scissors/Java/rock-paper-scissors.java

80 lines
2.1 KiB
Java

import java.util.Arrays;
import java.util.EnumMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.Random;
public class RPS {
public enum Item{
ROCK, PAPER, SCISSORS, /*LIZARD, SPOCK*/;
public List<Item> losesToList;
public boolean losesTo(Item other) {
return losesToList.contains(other);
}
static {
SCISSORS.losesToList = Arrays.asList(ROCK/*, SPOCK*/);
ROCK.losesToList = Arrays.asList(PAPER/*, SPOCK*/);
PAPER.losesToList = Arrays.asList(SCISSORS/*, LIZARD*/);
/*
SPOCK.losesToList = Arrays.asList(PAPER, LIZARD);
LIZARD.losesToList = Arrays.asList(SCISSORS, ROCK);
*/
}
}
//EnumMap uses a simple array under the hood
public final Map<Item, Integer> counts = new EnumMap<Item, Integer>(Item.class){{
for(Item item:Item.values())
put(item, 1);
}};
private int totalThrows = Item.values().length;
public static void main(String[] args){
RPS rps = new RPS();
rps.run();
}
public void run() {
Scanner in = new Scanner(System.in);
System.out.print("Make your choice: ");
while(in.hasNextLine()){
Item aiChoice = getAIChoice();
String input = in.nextLine();
Item choice;
try{
choice = Item.valueOf(input.toUpperCase());
}catch (IllegalArgumentException ex){
System.out.println("Invalid choice");
continue;
}
counts.put(choice, counts.get(choice) + 1);
totalThrows++;
System.out.println("Computer chose: " + aiChoice);
if(aiChoice == choice){
System.out.println("Tie!");
}else if(aiChoice.losesTo(choice)){
System.out.println("You chose...wisely. You win!");
}else{
System.out.println("You chose...poorly. You lose!");
}
System.out.print("Make your choice: ");
}
}
private static final Random rng = new Random();
private Item getAIChoice() {
int rand = rng.nextInt(totalThrows);
for(Map.Entry<Item, Integer> entry:counts.entrySet()){
Item item = entry.getKey();
int count = entry.getValue();
if(rand < count){
List<Item> losesTo = item.losesToList;
return losesTo.get(rng.nextInt(losesTo.size()));
}
rand -= count;
}
return null;
}
}