Weighted Random lot

WeightedRandom.java

package org.srkim.test;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

public class WeightedRandom {
	public static void main(String[] args) {
		List<Integer> lot = new ArrayList<Integer>();
		for (int i = 1; i < 46; i++) {
			lot.add(i);
		}
		
		// all the numbers have the same percentage to be selected.
		// now, add some weights on 2, 4 and 5.
		// 2, 4 or 5 is selected with a probability of 30 in 72.
		int[] a = { 1, 10, 1, 10, 10, 1, 1, 1, 1, 1, 
				1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
				1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
				1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
				1, 1, 1, 1, 1};
		int sum = 0;
		for (int i : a)
			sum += i;
		Random r = new Random();
		int s = r.nextInt(sum);
//		System.out.println(s + " " + sum);

		int prev_value = 0;
		int current_max_value = 0;
		int found_index = -1;
		for (int i = 0; i < a.length; i++) {
			current_max_value = prev_value + a[i];
			boolean found = (s >= prev_value && s < current_max_value) ? true : false;
			if (found) {
				found_index = i;
				break;
			}
			prev_value = current_max_value;
		}

		int selection = -1;
		if (found_index != -1) {
			selection = lot.get(found_index);
		}
		System.out.println(selection);

	}
}