java編寫雙色球源代碼。-----系統作為彩票雙色球生成器，模擬機選一注雙色球的彩票號碼

package demo2;
import java.util.Arrays;
import java.util.Random;
/**
 * 系統作為彩票雙色球生成器，模擬機選一注雙色球的彩票號碼：
 * 	1、需要從“01”到“32”中隨機選擇出6個數字作為紅色球且這6個數字不能重復；
 * 	2、並從”01”到”07”中隨機選擇一個數字作為藍色球；
 * 	3、7個數字合到一起作為一注雙色球彩票的號碼；
 */
public class DoubleBall {
	public static void main(String[] args) {
		String[] RED_BALLS = { "01", "02", "03", "04", "05", "06", "07", "08",
				"09", "10", "11", "12", "13", "14", "15", "16", "17", "18",
				"19", "20", "21", "22", "23", "24", "25", "26", "27", "28",
				"29", "30", "31", "32" };
		String[] BLUE_BALLS = { "01", "02", "03", "04", "05", "06", "07" };
		boolean[] redFlags = new boolean[RED_BALLS.length];
		String[] redBalls = new String[6];
		String blueBall;
		Random ran = new Random();
		// red
		for (int i = 0; i < redBalls.length; i++) {
			int index;
			do {
				index = ran.nextInt(RED_BALLS.length);
			} while (redFlags[index]);
			/**
			 * redFlags[index]用途：
			 * 	當redFlags[index]=true表示已經重復，所以你需要
			 * 	再執行do當中的代碼重新獲取index
			 */
			redBalls[i] = RED_BALLS[index];
			redFlags[index] = true;
		}
		// blue
		blueBall = BLUE_BALLS[ran.nextInt(BLUE_BALLS.length)];
		Arrays.sort(redBalls);
		System.out.println("**********本期開獎**********");
		System.out.println("紅球: ");
		for (int i = 0; i < redBalls.length; i++) {
			System.out.print("(" + redBalls[i] + ") ");
		}
		System.out.println();
		System.out.println("籃球: ");
		System.out.print("(" + blueBall + ") ");
	}
}