java 微信随机红包算法代码实例

 public static double [] getMoney(double money, int num){
    Random r = new Random();
    DecimalFormat format = new DecimalFormat(".##");
    
    double middle = Double.parseDouble(format.format(money/num));
    double [] dou = new double[num];
    double redMoney = 0;
    double nextMoney = money;
    double sum = 0;
    int index = 0;
    for(int i=num;i>0;i--){
      if(i == 1){
        dou[index] = nextMoney;
      }else{
        while(true){
          String str = format.format(r.nextDouble()*nextMoney);
          redMoney = Double.parseDouble(str);
          if(redMoney>0 && redMoney < middle){
            break;
          }
        }
        nextMoney = Double.parseDouble(format.format(nextMoney - redMoney));
        sum = sum + redMoney;
        dou[index] = redMoney;
        middle = Double.parseDouble(format.format(nextMoney/(i-1)));
        index++;
      }
    }
    return dou;
  }