vrp-tabu-search/src/example/vrp/Algorithms.js

Tabu Search Algorithm for Vehicle Routing Problem

/**
 * Created by tnlam on 5/7/15.
 */

var util = require('util');
var assert = require('assert');
var defineClass = require('simple-cls').defineClass;
var Matrix = require('sylvester').Matrix;
var Vector = require('sylvester').Vector;

var VRPSolution = require('./Solution.js');

var TS = require('../../core/TS.js');

function neighbors (candidate) {
  //console.log('candidate ne');
    //console.log(candidate);
    assert(this.problem.valid(candidate));
    var self = this;
    var neighbors = [];
  //console.log(this.problem);
    var N = this.problem.dimension(); // number of city nodes
  //console.log('N = ' + N);
    var E = N; // number of travel paths
    // enumerate all possible pair of edges to remove
    //var origin = candidate.data.elements.slice(0);
    //console.log(origin);

  for (var i = 0; i < N-1; i++) {
    for (var j = 1; j < N; j++) {
      var ar = [];

      for (var k = 0; k < candidate.data.elements.length; k++) {
        ar.push(candidate.data.elements[k].slice());
      }
      //console.log('-ar');
      //console.log(ar);
      var r1 = ar[i];
      var r2 = ar[j];
      //console.log('original r1: ' + r1);
      //console.log('original r2: ' + r2);

      for (var x = 1; x < r1.length-1; x++) {
        for (var y = 1; y < r2.length-1; y++) {
          //console.log('x = ' + x + ', y = ' + y);
          var tmp = r1[x];
          r1[x] = r2[y];
          r2[y] = tmp;

          //console.log('so sanh');
          //console.log(self.problem.demand(r1) <= self.problem.capacity);
          //console.log(self.problem.demand(r2) <= self.problem.capacity);
          if (self.problem.demand(r1) <= self.problem.capacity &&
              self.problem.demand(r2) <= self.problem.capacity) {
            //console.log('r1: ' + r1 + ', demands = ' + self.problem.demand(r1));
            //console.log('r2: ' + r2 + ', demands = ' + self.problem.demand(r2));
            ar[i] = r1.slice();
            ar[j] = r2.slice();

            //console.log(ar);
            //console.log(new VRPSolution($V($V(ar))));
            //if (i == 0 && j == 1 && x == 1 && y == 1) {
            //  console.log('hehe: ');
            //  console.log(new VRPSolution($V($V(ar))));
            //  ar.forEach(function (a) {
            //    console.log(self.problem.demand(a));
            //  });
              neighbors.push(new VRPSolution($V($V(ar))));
            //}
          }
        }
      }
    }
  }

    //console.log('-neighbors-');
    //console.log(neighbors);

    var unique_neighbors = [];

  neighbors.forEach(function (neighbor) {
    var duplicate = unique_neighbors.some(function (elem) {
      return neighbor.identical(elem);
    });
    duplicate = duplicate || candidate.identical(neighbor);
    //console.log(duplicate);
    if (!duplicate) {
      neighbor.fitness = self.problem.fitness(neighbor); //make sure we evaluate the neighbor before returning
      //console.log('neighbor fitness: ' + neighbor.fitness);
      unique_neighbors.push(neighbor);
    }
  });

    //console.log('unique_neighbors');
    //console.log(unique_neighbors);
    assert(unique_neighbors.length > 0, "unique neighborhood set is empty!");
    return unique_neighbors;
}

function neighbor (candidate) {
    assert(this.problem.valid(candidate));
    var N = this.problem.dimension(); //number of city nodes
    var E = N; //number of travel paths
    var origin = candidate.data.elements.slice(0);
}

var VRP_TS = defineClass({
    name: 'VRP_TS',
    extend: TS,
    methods: {
        'neighbors': neighbors,
        'neighbor' : neighbor
    }
});

module.exports.VRP_TS = VRP_TS;