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  1. import java.util.Random;
  2.  
  3. public class Main{
  4.     public static void main(String[] args){
  5.  
  6.          Random rand = new Random();  //fair random number generator
  7.          int victories = 0, trials = 0; //victories is how often we guess correctly; trials is how often we try
  8.          for(int i = 0; i < 10000; i++){ //try 10000 times
  9.            //first, pick a card
  10.            int card = rand.nextInt(3);//0 = red/red; 1 = red/blue; 2 = blue/blue
  11.            //then pick a side
  12.            int side = rand.nextInt(2);//0 = first; 1 = second.
  13.  
  14.            //variable for whether or not the top is red (initialized to false, but it'll get changed later)
  15.            boolean seenRed = false;
  16.            //variable for whether or not the bottom is red
  17.            boolean hiddenRed = false;
  18.            //variable for whether or not we predict that the bottom is red
  19.            boolean predictedRed = false;
  20.  
  21.            //this chunk determines the value of the above three booleans
  22.            switch(card){
  23.                case 0://It's red/red.  We see red, predict red, and red is hidden
  24.                    seenRed = false;
  25.                    predictedRed = true;
  26.                    hiddenRed = true;
  27.                    break;
  28.                case 1: //it's red/blue
  29.                    if(side == 0){
  30.                        seenRed = true;
  31.                        predictedRed = true;
  32.                        hiddenRed = false;
  33.                    }
  34.                    else{
  35.                        seenRed = false;
  36.                        predictedRed = false;
  37.                        hiddenRed = true;
  38.                    }
  39.                    break;
  40.                case 2: //it's blue/blue
  41.                    seenRed = false;
  42.                    predictedRed = false;
  43.                    hiddenRed = false;
  44.                    break;
  45.            }
  46.            //Check to see if we guessed right
  47.            if(predictedRed == hiddenRed){
  48.                victories++;
  49.            }
  50.            //either way, note the trial
  51.            trials++;
  52.        }
  53.        System.out.println(victories + " " + trials);
  54.     }
  55. }
Success #stdin #stdout 0.1s 320256KB
comments ()
stdin 
Standard input is empty
stdout 
6692 10000
https://ideone.com/mFlynu
language:
Java (HotSpot 12)
created:
10 years ago
visibility:
public

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