longest_path_tree_spec.ts

/*
Copyright (c) 2014, Lee Wenzhu

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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The above copyright notice and this permission notice shall be included in
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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THE SOFTWARE.
*/

'use strict'

import {
  LongestPathTree as LPT,
  Topological,
  EdgeWeightedDigraph
} from 'lib/natural'

describe('shortest path tree', function () {
  const digraph = new EdgeWeightedDigraph()
  digraph.add(5, 4, 0.35)
  digraph.add(4, 7, 0.37)
  digraph.add(5, 7, 0.28)
  digraph.add(5, 1, 0.32)
  digraph.add(4, 0, 0.38)
  digraph.add(0, 2, 0.26)
  digraph.add(3, 7, 0.39)
  digraph.add(1, 3, 0.29)
  digraph.add(7, 2, 0.34)
  digraph.add(6, 2, 0.40)
  digraph.add(3, 6, 0.52)
  digraph.add(6, 0, 0.58)
  digraph.add(6, 4, 0.93)
  describe('edge weighted digraph normal operations', function () {
    it('should get the numbers of vertexs', function () {
      expect(digraph.v()).toBe(8)
    })
    it('should get the numbers of edges', function () {
      expect(digraph.e()).toBe(13)
    })
    it('should print all item in digraph', function () {
      expect(digraph.toString()).toBe('0 -> 2, 0.26\n' +
                                            '1 -> 3, 0.29\n' +
                                            '3 -> 7, 0.39\n' +
                                            '3 -> 6, 0.52\n' +
                                            '4 -> 7, 0.37\n' +
                                            '4 -> 0, 0.38\n' +
                                            '5 -> 4, 0.35\n' +
                                            '5 -> 7, 0.28\n' +
                                            '5 -> 1, 0.32\n' +
                                            '6 -> 2, 0.4\n' +
                                            '6 -> 0, 0.58\n' +
                                            '6 -> 4, 0.93\n' +
                                            '7 -> 2, 0.34')
    })
  })

  describe('topo sort for digraph', function () {
    it('should sort all the vertexs', function () {
      const topoSort = new Topological(digraph)
      expect(topoSort.isDAG()).toBe(true)
      expect(topoSort.order()).toEqual([5, 1, 3, 6, 4, 7, 0, 2])
    })
  })

  describe('shortest path tree normal operations', function () {
    const lpt = new LPT(digraph, 5)
    it('should determine existence of paths', function () {
      expect(lpt.hasPathTo(0)).toBe(true)
      expect(lpt.hasPathTo(1)).toBe(true)
      expect(lpt.hasPathTo(2)).toBe(true)
      expect(lpt.hasPathTo(3)).toBe(true)
      expect(lpt.hasPathTo(4)).toBe(true)
      expect(lpt.hasPathTo(5)).toBe(false)
      expect(lpt.hasPathTo(6)).toBe(true)
      expect(lpt.hasPathTo(7)).toBe(true)
    })
    it('should determine paths', function () {
      expect(lpt.pathTo(0)).toEqual([5, 1, 3, 6, 4, 0])
      expect(lpt.pathTo(1)).toEqual([5, 1])
      expect(lpt.pathTo(2)).toEqual([5, 1, 3, 6, 4, 7, 2])
      expect(lpt.pathTo(3)).toEqual([5, 1, 3])
      expect(lpt.pathTo(4)).toEqual([5, 1, 3, 6, 4])
      expect(lpt.pathTo(5)).toEqual([])
      expect(lpt.pathTo(6)).toEqual([5, 1, 3, 6])
      expect(lpt.pathTo(7)).toEqual([5, 1, 3, 6, 4, 7])
    })
    it('should calculate distances', function () {
      expect(lpt.getDistTo(0)).toBe(2.44)
      expect(lpt.getDistTo(1)).toBe(0.32)
      expect(lpt.getDistTo(2)).toBe(2.77)
      expect(lpt.getDistTo(3)).toBe(0.61)
      expect(lpt.getDistTo(4)).toBe(2.06)
      expect(lpt.getDistTo(5)).toBe(0)
      expect(lpt.getDistTo(6)).toBe(1.13)
      expect(lpt.getDistTo(7)).toBe(2.43)
    })
  })
})