Java weighted randomization algorithm

Question

Hi All,

Trying to find optimal way to write weighted randomization algorithm in java.

I have an enum value which has corresponding weight and depending on weighted randomization, need to pick the appropriate enum. Appreciate any help on this. Thank you!

Answer 1

import java.util.Scanner;

class Nagm

{

class EnumWeight

{

protected long enumVal;

protected double weight;

public EnumWeight ( long longEnumVal, double dblWeight) { enumVal=longEnumVal; weight = dblWeight; }

public long GetEnumValue() { return(enumVal); }

public double GetWeight() { return(weight); }

}

long GetNumValue (EnumWeight A[], double weight)

{

long longIntNumReturn = 0;

int iIndexPos;

int N = A.length;

double firstWeight=A[0].GetWeight();

double lastWeight=A[N-1].GetWeight();

//linear search

if (weight > firstWeight && weight <= lastWeight)

{

for (iIndexPos=0; iIndexPos<A.length; iIndexPos++)

{

if (A[iIndexPos].GetWeight() > weight)

{

break;

}

}

EnumWeight below = A[iIndexPos-1];

EnumWeight above = A[iIndexPos];

double aboveDiff = Math.abs(above.GetWeight()-weight);

double belowDiff = Math.abs(below.GetWeight()-weight);

longIntNumReturn = ( aboveDiff > belowDiff) ? below.GetEnumValue() : above.GetEnumValue();

}

else

{

if (weight > lastWeight)

{

longIntNumReturn = N-1;

}

}

return(longIntNumReturn);

}

public void Go()

{

Scanner scanner = new Scanner(System.in);

EnumWeight A[] = new EnumWeight[18];

A[0] = new EnumWeight(1,24);

A[1] = new EnumWeight(2,32);

A[2] = new EnumWeight(3,36);

A[4] = new EnumWeight(4,42);

A[5] = new EnumWeight(5,48);

A[6] = new EnumWeight(6,52);

A[7] = new EnumWeight(7,56);

A[8] = new EnumWeight(8,60);

A[9] = new EnumWeight(9,64);

A[10] = new EnumWeight(10,72);

A[11] = new EnumWeight(11,76);

A[12] = new EnumWeight(12,80);

A[13] = new EnumWeight(13,84);

A[14] = new EnumWeight(14,88);

A[15] = new EnumWeight(15,92);

A[16] = new EnumWeight(16,96);

A[17] = new EnumWeight(18,100);

System.out.print(" Please input the weight :> ");

double weight = scanner.nextDouble();

System.out.println(" enum value for weight " + weight + " is " + GetNumValue(A,weight));

}

public static void main(String args[])

{

Nagm x = new Nagm();

x.Go();

}

}