Java (vi)--lottery system

General idea:

Add the number to the ArrayList dynamic array, use the static method of the set collections.shuffle () the elements in the sequence set to get the random number,remove Delete a drawn number

The code is as follows:

1 Importjava.util.ArrayList;2 Importjava.util.Collections;3 ImportJava.util.Random;4 5  Public classRaffle {6 7     PrivateArraylist<integer>list;8     9     Private voiddeal () {Ten         //adds a specified number of num integers to the list container in order One         if(list==NULL) { AList =NewArraylist<integer>(); -              for(inti = 1; i < 1000; i++) { - List.add (i); the             }  -         }                 -         //To disrupt the order of elements in a list - collections.shuffle (list);  +     } -      +     //Lottery Method: Draw a specified number of prizes A      Public voidDraw () { atRandom Rdom =NewRandom (); -          -         intindex =Rdom.nextint (List.size ()); -System.out.println ("First prize:" +List.get (index)); - List.remove (index); - collections.shuffle (list); in          -          to          for(inti = 0; I < 2; i++) { +             intIndex2 =Rdom.nextint (List.size ()); -System.out.println ("Second Prize:" +list. Get (INDEX2)); the List.remove (INDEX2);  *         } $ collections.shuffle (list);Panax Notoginseng          -          the          for(inti = 0; I < 3; i++) { +             intIndex3 =Rdom.nextint (List.size ()); ASystem.out.println ("Third prize:" +list. Get (INDEX3)); the List.remove (index3); +         } - collections.shuffle (list); $     } $      -      -      Public Static voidMain (string[] args) { the         //TODO auto-generated Method Stub -Raffle RF =NewRaffle ();Wuyi rf.deal (); the Rf.draw (); -  Wu     }     -}

Operation Result:

Java (vi)--lottery system