Shulou(Shulou.com)05/31 Report--

This article mainly explains "how to realize the lucky draw algorithm in Java". Interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn "how to realize the lucky draw algorithm by Java".

Description of the topic

Topic: in order to give benefits to fans, Xiao Xuzhu decided to pick a lucky fan among the fans who participated in learning to sign in and give them a small gift. In order to be fair, make sure that the lottery process is random.

Second, the way to solve the problem

1. Add the participants to the collection

2. Use Random object to get random numbers

3. Use the random number as the subscript to get the lucky users in the set

3. Public class Basics28 {public static void main (String [] args) {List luckUserNames = getLuckUserNames (); Random random = new Random (); int luckNum = random.nextInt (6); System.out.println ("the lucky future boss is: + luckUserNames.get (luckNum));} private static List getLuckUserNames () {List luckUserNames = new ArrayList (); luckUserNames.add (" Li slowly _ ") LuckUserNames.add ("TryAgain-"); luckUserNames.add ("team_dog"); luckUserNames.add ("Jasonakeke"); luckUserNames.add ("Xiao Wang who is good at learning c language"); luckUserNames.add ("Ara~ running after the wind"); return luckUserNames;}}

Fourth, optimize the lottery algorithm to solve the problem.

The random number is too small and needs to be optimized.

It is necessary to list the number of random hits by everyone and show it, which is more open and fair.

The code details public class LuckDraw {public static void main (String [] args) {List luckUserNames = getLuckUserNames (); Random random = new Random (); / / key:luckNum, value:count Map luckNumMap = new HashMap (); for (int I = 0; I < 100; iTunes +) {int luckNum = random.nextInt (4); Integer count = luckNumMap.get (luckNum) If (count==null) {count= 0;} + count; luckNumMap.put (luckNum,count);} Integer maxLuckNum = 0; Integer maxCount = 0; for (Integer luckNum:luckNumMap.keySet ()) {if (maxCount)

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