Adjacency List / Adjacency Matrix

Question

Hello All,
I am very new to Java programming and looking for some examples:
1) How I can create an Adjacency List structure consisting of random numbers in a form of Skewed, Uniform, or Two-Tier Distributions.
2) Create a matrix (two-dimentional array, and this part is easy). The difficult part is how can I create two dimentional array with random number distribution for 1's and 0's (i.e. adjacency matrix) in a form of Skewed, Uniform, or Two-Tier Distributions.
Thank you!

Answer 1

If I'm getting this right, I think the 2 problems above are down to one question:
1) How to create a random number generation method for {Skewed, Uniform, Two-Tier, ...} Distribution?
One solution I can immediately think of is as follows:
import static java.lang.Math.*;
// Cumulative Distribution Function
public interface CDF {
    // probability by a given x
    double p(double x);
    // x from a given probability p
    double x(double p);
// Example - Normal Distribution
public class NormalDistribution implements CDF {
    private double mean, sd;
    public NormalDistribution(double mean, double sd) {
        this.mean = mean;
        this.sd = sd;
    private double phi(double z) {
        double t = 1.0 / (1.0 + 0.2316419 * x);
        return 1.0 - (exp(-z*z / 2.0) / sqrt(2.0 * PI)) * (0.31938153 * t - 0.356563782 * pow(t, 2.0) + 1.781477937 * pow(t, 3.0) - 1.821255978 * pow(t, 4.0) + 1.330274429 * pow(t, 5.0));
    private double inversePhi(double p) {
        double a = p > 0.5 ? 1.0 - p : p;
        double t = sqrt(log(1.0 / (p*p)));
        double t2 = t*t, t3 = t2*t;
        return (p > 0.5 ? 1.0 : -1.0) * (t - (2.515517 + 0.802853 * t + 0.010328 * t2) / (1 + 1.432788 * t + 0.189269 * t2 + 0.001308 * t3));
    public double p(double x) {
        return phi((x - mean) / sd);
    public double x(double p) {
        return inversePhi(p) * sd + mean;
// RandomNumberGenerator
public class RNG<T extends CDF> {
    private T dist;
    public RNG(T dist) {
        this.dist = dist;
    public double rand() {
        return x(rand());
}Thus with the following line:
RNG NR = new RNG<NormalDistribution>(new NormalDistribution(10.0, 5.0));You'll have NR as a random number generator that will give numbers that are normally distributed.
Of course if you just need discrete distributions instead of continuous ones, you can make similar definitions using long or int instead of double
Hope this helps~
Alex Lam S.L.