<"color: #ff0000">下面再给大家分享一段实例代码基于Java实现中奖概率计算

 做移动的项目，有个需求，做个摇奖的活动！其中中奖的计算比较恶心，用户要改动各个奖项的中奖概率，而且每天的奖项有个数限制。一二三四五六等奖，概率不通，怎么算一个用户参与了中没中将呢？苦思了一下，可以用Random类的 nextInt(int x)方法产生一个范围内的随机数，产生到那个区间就是几等奖了，中奖区间的产生是动态的。贴出源代码，仅供参考！


package Mzone;
import java.util.ArrayList;
import java.util.Random;
public class Mzone {
 /**
 * CopyRright(c)2009-04: 
 * Project: 
 * Module ID: 
 * Comments: 概率计算
 * JDK version used: <JDK1.4>
 * Author：ch
 * Create Date：2009-04-20
 * Modified By： 
 * Modified Date: 
 * Why & What is modified 
 * Version: 1.0
 */ 
 static Random r = new Random();
 public static void main(String[] args) {
  //各个奖项的中奖概率的分母
  Integer _5m = new Integer(5);
  Integer _500m = new Integer(30);
  Integer _ipod = new Integer(500);
  Integer _phone = new Integer(1000);
  Integer _notebook = new Integer(1500);
  Integer _jay = new Integer(50);
  ArrayList list = new ArrayList();
  if(_5m.intValue()!=0)
   list.add(_5m);
  if(_500m.intValue()!=0)
   list.add(_500m);
  if(_ipod.intValue()!=0)
   list.add(_ipod);
  if(_phone.intValue()!=0)
   list.add(_phone);
  if(_notebook.intValue()!=0)
   list.add(_notebook);
  if(_jay.intValue()!=0)
   list.add(_jay);
  //计算最小公倍数
  int common = getN(list);
  System.out.println("最小公倍数:"+common);
  int a = 0;int b = 0;int c = 0;int d = 0;int e = 0;int f = 0;int g = 0;
  int first = 0;int second = 0;int third = 0;int four = 0;int fifth = 0;int sixth = 0;
  if(_5m.intValue()!=0){
   first = common/_5m.intValue();
  }
  if(_500m.intValue()!=0){
   second = first + (common/_500m.intValue());
  }else second = first;
  if(_ipod.intValue()!=0){
   third = second + (common/_ipod.intValue());
  }else third = second;
  if(_phone.intValue()!=0){
   four = third + (common/_phone.intValue());
  }else four = third;
  if(_notebook.intValue()!=0){
   fifth = four + (common/_notebook.intValue());
  }else fifth = four;
  if(_jay.intValue()!=0){
   sixth = fifth + (common/_jay.intValue());
  }else sixth = fifth;
  int times = 30000;//循环次数
  for(int i = 0;i < times; i++){
   int ri = getRandom(common);//产生随机数
   if(ri >= 0 && ri < first){
    a++;
   }else if(ri >= first && ri < second){
    b++;
   }else if(ri >= second && ri < third){
    c++;
   }else if(ri >= third && ri < four){
    d++;
   }else if(ri >= four && ri < fifth){
    e++;
   }else if(ri >= fifth && ri < sixth){
    f++;
   }else{
    g++;
   }
  }
  System.out.println("5m值:" + a + " 500m值:" + b + " ipodMP3:" + c + " 手机:" + d + " 笔记本电脑:" + e + " 演唱会门票:" + f + " 谢谢参与:" + g);
 }
 /**
  * 求最大公约数
 */
 public static int gcd(int m, int n){
  while (true){
   if ((m = m % n) == 0)
   return n;
   if ((n = n % m) == 0)
   return m;
  }
 }
 /**
 * 求最小公倍数
 */
 public static int gys(int z, int y){
  int t = 0;
  int c = 0;
  c = gcd(z,y);
  t = z * y / c;
  return t;
 }
 /**
  * 求几个数的最小公倍数
 */
 public static int getN(ArrayList list){
  int t = 1;
  for(int i = 0;i<list.size();i++){
   Integer temp = (Integer)list.get(i);
   t = gys(t,temp.intValue());
  }
  return t; 
 }
 /**
  * 产生随机数
 */
 public static int getRandom(int y){
  int result = r.nextInt(y);
  return result;
 }
}