jpayne@68: package fun;
jpayne@68: 
jpayne@68: import java.util.Locale;
jpayne@68: import java.util.Random;
jpayne@68: 
jpayne@68: import shared.Parse;
jpayne@68: import shared.Shared;
jpayne@68: 
jpayne@68: public class Chance {
jpayne@68: 	
jpayne@68: 	//Probability of something with a chance of X happening at least Y times in Z chances
jpayne@68: 	public static void main(String[] args){
jpayne@68: 		
jpayne@68: 		int draws;
jpayne@68: 		int minSuccess;
jpayne@68: 		float prob;
jpayne@68: 		long rounds;
jpayne@68: 		try {
jpayne@68: 			draws = Parse.parseIntKMG(args[0]);
jpayne@68: 			minSuccess = Parse.parseIntKMG(args[1]);
jpayne@68: 			prob = Float.parseFloat(args[2]);
jpayne@68: 			rounds = Parse.parseKMG(args[3]);
jpayne@68: 		} catch (Exception e) {
jpayne@68: 			System.err.println("Chance (int)draws (int)minSuccess (float)prob (int)rounds");
jpayne@68: 			System.exit(1);
jpayne@68: 			throw new RuntimeException();
jpayne@68: 		}
jpayne@68: 		
jpayne@68: 		Random randy=Shared.threadLocalRandom();
jpayne@68: 		
jpayne@68: 		long passes=0;
jpayne@68: 		for(long i=0; i<rounds; i++){
jpayne@68: 			int pass=runOneRound(randy, draws, minSuccess, prob);
jpayne@68: 			passes+=pass;
jpayne@68: 		}
jpayne@68: 		
jpayne@68: 		double odds=passes*1.0/rounds;
jpayne@68: 		System.err.println("Probability: "+String.format(Locale.ROOT, "%.6f%%", 100*odds));
jpayne@68: 	}
jpayne@68: 
jpayne@68: 	private static int runOneRound(Random randy, int draws, int minSuccess, float prob) {
jpayne@68: 		int success=0;
jpayne@68: 		for(int i=0; i<draws && success<minSuccess; i++){
jpayne@68: 			if(randy.nextFloat()<=prob){success++;}
jpayne@68: 		}
jpayne@68: 		return (success>=minSuccess ? 1 : 0);
jpayne@68: 	}
jpayne@68: 	
jpayne@68: }