Micro-letter random generation of red envelope amount algorithm Java version _java

In recent years to play the most crazy should be red envelopes, especially when the new Year is particularly popular, the following write a red envelope of the random algorithm, in fact quite simple, is to provide a way of thinking, hope to give you some inspiration.

public class wxalgorithm{

 /**
 * @param moneysum Enter total amount
 * @param rednum Enter the number of red envelopes * *
 private static void W Xalgorithm (double moneysum, int rednum) {
 //Set smallest amount
 double moneymin = 0.01;
 Random Random = new Random ();
 Exact decimal point 2-bit
 numberformat formatter = new DecimalFormat ("#.##");
 for (int i=1;i<rednum;i++)
 {
   //random number, numeric range between minimum value and balance String money
   = Formatter.format ( Random.nextdouble () * (moneysum-moneymin) + moneymin);
   numeric conversion
       moneysum = double.valueof (Formatter.format (moneysum-double.valueof (Money));
  
   System.out.println ("The" "+i+" a red envelope: "+ Money +" Yuan, Balance: "+ moneysum);
 }
 
 System.out.println ("Last red envelope:" + moneysum + "Yuan, Balance:" + (Moneysum-moneysum));
 }
 
 public static void Main (string[] args) {
 wxalgorithm (10.26, 9);
 }
}

Later on the internet to collect a number of micro-letters randomly generated red envelope algorithm for everyone's reference.

 public static double [] Getmoney (double, 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; }

One of the basic ideas here is this: first calculate the average value of red envelopes, and then through a random red packets less than the average number of red envelopes, when the red envelopes, the total amount of red envelopes need to be correspondingly reduced, and recalculate the average: The new total amount (the original total red envelope number-1), until the last red envelope, Cram all the remaining money into it.

There are many wonderful source sharing: Java simple to rob red envelopes random allocation of red envelopes algorithm to achieve the source code.

Package com.sunron.test;

Import Java.math.BigDecimal;

Import Org.junit.Test;

public class Hongbao {
 @Test public
 void Testhonbao () {
 HB (100, 9, 0.01);//amount, number, minimum value
 //zb ();
 }
 void HB (double total,int num,double min) {for
 (int i=1;i<num;i++) {
  double safe_total= (total-(num-i) *min) /(num-i);
  Double Money=math.random () * (safe_total-min) +min;
  BigDecimal money_bd=new BigDecimal (money);
  Money=money_bd.setscale (2,BIGDECIMAL.ROUND_HALF_UP). Doublevalue (); 
  Total=total-money;
  BigDecimal total_bd=new BigDecimal (total);
  Total=total_bd.setscale (2,BIGDECIMAL.ROUND_HALF_UP). Doublevalue ();
  System.out.println ("The" "+i+" a red Envelope: "+money+", the balance is: "+total+");
 }
 System.out.println ("+num+" "a red Envelope:" +total+ ", the balance is: 0 Yuan");
 }
 
 void Zb () {for
     (int a=0;a<=10000;a++) {
      if (a% 1000== 0) 
      System.out.println (a);
     }

}}

When someone is robbing a red envelope, we're going to study the random red Envelope algorithm:

public static void Main (string[] args) {//red packets int number = 10;
    Total amount of red envelopes = 100;
    float money;
    Minimum red packet double min = 1;
    Double Max;
    int i = 1;
    List math = new ArrayList ();
    DecimalFormat df = new DecimalFormat ("###.##");
      while (I < number) {//Guarantee even if a red envelope is the largest, the remaining red envelopes, each red envelope will not be less than the minimum value max = Total-min * (number-i);
      int k = (int) (number-i)/2;
      Ensure that the last two persons take the red envelopes not exceeding the remaining red envelopes if (Number-i <= 2) {k = number-i;
      //maximum red envelope limit of the average line up and down max = max/k;
      Ensure that each red envelope is greater than the minimum value and will not be greater than the maximum money = (int) (min * + math.random () * (max * 100-min * 100 + 1));
      Money = (float) money/100;
      Reserve two decimal money = Float.parsefloat (Df.format);
      total= (int) (TOTAL*100-MONEY*100);
      Total = total/100;
      Math.add (Money);
      System.out.println ("First" + i + "personal get" + Money + "left" + total);
      i++;
 The last person to take the remaining red envelopes if (i = = number) {Math.add (total);       System.out.println ("First" + i + "personal get" + total + "left 0");
  }//Fetch the index of the largest value in the array System.out.println ("The first in this round of red envelopes" + (Math.indexof (Collections.max (math) + 1) + "Personal luck best"); }

The above is for you to share a variety of micro-letter random red envelope algorithm, for you to provide a variety of ideas, I hope to learn how to use micro-letter random red envelope algorithm to help, but also hope that we continue to pay attention to the cloud-dwelling community more wonderful content.