Brownian Backgammon simulation to test doubling strategies

Question118566.java

import java.util.Random;

public class Question118566 {
    public static void main (String [] args) {
	double lambda0 = Double.parseDouble (args [0]);
	double k0 = Double.parseDouble (args [1]);
	double lambda1 = Double.parseDouble (args [2]);
	double k1 = Double.parseDouble (args [3]);

	int ntrials = 100000;

	final int L = 100;

	int sum0 = 0;
	int sum1 = 0;

	Random random = new Random (0);
	
	for (int n = 0;n < ntrials;n++) {
	    int pos = L / 2;
	    int owner = -1;
	    int value = 1;
	    
	    for (;;) {
		if (random.nextBoolean ())
		    pos++;
		else
		    pos--;
		if (pos == 0) {
		    sum0 += value;
		    break;
		}
		if (pos == L) {
		    sum1 += value;
		    break;
		}

		if (owner == -1) {
		    if (pos <= L * (1 - lambda0)) {
			// player 0 tries to double
			if (pos <= L * (1 - lambda1)) {
			    // player 1 resigns
			    sum0 += value;
			    break;
			}
			// player 1 accepts
			value *= 2;
			owner = 1;
		    }
		    else if (pos >= L * lambda1) {
			// player 1 tries to double
			if (pos >= L * lambda0) {
			    // player 0 resigns
			    sum1 += value;
			    break;
			}
			// player 0 accepts
			value *= 2;
			owner = 0;
		    }
		}
		else if (owner == 0) {
		    if (pos <= L * (1 - k0)) {
			// player 0 tries to double
			if (pos <= L * (1 - k1)) {
			    // player 1 resigns
			    sum0 += value;
			    break;
			}
			// player 1 accepts
			value *= 2;
			owner = 1;
		    }
		}
		else { // owner == 1
		    if (pos >= L * k1) {
			// player 1 tries to double
			if (pos >= L * k0) {
			    // player 0 resigns
			    sum1 += value;
			    break;
			}
			// player 0 accepts
			value *= 2;
			owner = 0;
		    }
		}
	    }
	}

	System.out.println ("points for 0 : " + sum0);
	System.out.println ("points for 1 : " + sum1);
    }
}