Genetic I

/*

This code does the following:

1 - Start a new population of 50 "numbers" and a GOAL of 9999
2 - Select the two highest multiple of 3 available
3 - Create a new generation of numbers ranging between it's parents values, incresing a little
4 - Do that until reaches the GOAL

*/

var GOAL = 9999;
var SIZE = 50;
var MULTIPLE_OF = 3;
var INCREASE = MULTIPLE_OF;

function getRandom(minNum, maxNum) {
    if (minNum == null) {
        minNum = 0;
    }
    
    if (maxNum == null) {
        throw new Error('getRandom was called without a maxNum');
    }
    
    return Math.floor(Math.random() * (maxNum - minNum)) + minNum;
}

function selectCouple(members) {
    var sorted = members.filter(function (member) {
        return member % MULTIPLE_OF === 0;
    }).sort();
    
    if (!sorted || sorted.length < 2) {
        throw new Error('Extinction!')
    }
    
    return [sorted[sorted.length - 2], sorted[sorted.length - 1]];
}

function Pop () {
    var member;
    this.members = [];
    console.log('Starting Population with these members:');
    for (var i = 0; i < SIZE; i++) {
        member = getRandom(null, GOAL);
        this.members.push(member);
        console.log(' - ' + member);
    }
}

Pop.prototype.isDone = function (last) {
    this.rounds = this.rounds || 1;
    
    console.log('Round ' + this.rounds);
    
    if (last >= GOAL) {
        console.log('=========')
        console.log('Done! In ' + this.rounds + ' rounds');
        return true;
    }
    
    this.rounds++;
    return false;
}

Pop.prototype.generate = function () {
    var selectedMembers = selectCouple(this.members);
    var first = selectedMembers[0];
    var last = selectedMembers[1];
    
    if (first === last) {
        last = last + INCREASE;
    }
    
    if (this.isDone(last)) {
        return;
    }
    
    var member;
    this.members = [];
    console.log('New generation for [' + first.toString()  + ', ' + last.toString() + ']');
    
    for (var i = 0; i < SIZE; i++) {
        member = getRandom(first, last + INCREASE);
        this.members.push(member);
        console.log(' - ' + member);
    }
    
    this.generate();
}

var pop = new Pop();
pop.generate();