Example of random algorithm for double color ball lottery implemented in Java

This is my first time writing a technical blog, and I will write about a random algorithm for a double color ball lottery that I wrote before.

The principle is as follows:

1 First initialize an array nums to be drawn, the length of the array is k

2. Randomly select a random number between 1-k to get nums [k], in this way, the first lottery number is obtained, and the number is deleted from nums, k--.

3. Repeat step 2 until you get all the winning numbers

 1 class myLuck 
 2 {        
 3     private int mTarget;    
 4     List<Integer> mNums = new ArrayList<Integer>(); //摇奖池 5      6     ///从多少个数中产生多少个数 7     ///例如 33选6 则Source=33，Target=6； 8     myLuck(int vSource,int vTarget) {        
 9         for (int i = 1; i <=vSource ; i++) {            
10             mNums.add(i);11         }12         mTarget=vTarget;13     }14     15     public String GetNums()16     {        
17         String xString="";18         for (int i =0;i<mTarget; i++) 
19         {20             int _index=(int)(Math.random()* mNums.size());21             xString+=mNums.get(_index)+" ";22             //System.out.print("("+(_index+1)+")"+mNums.get(_index)+"-");    
23             //如何删除一个元素24             mNums.remove(_index);25         }    
26         return xString;27     }    
28 }

The calling method is as follows:

myLuck _red=new myLuck(33, 6);
myLuck _blue=new myLuck(16,1);
String Str =_red.GetNums() +","+_blue.GetNums();

It’s very simple, just output the result~

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