lite-pathfindings/dist/algorithms/Djikstra.js

Simple, intuitive and lightweight pathfinding algorithms

"use strict";

module.exports = {
  init: function init(EdgeMap, sDeb) {
    var A = EdgeMap;

    var S = [];
    for (var vertex in A) {
      S.push(vertex);
    }

    var d = [];
    S.forEach(function (s) {
      d[s] = Number.POSITIVE_INFINITY;
    });

    d[sDeb] = 0;

    var Q = S.concat();
    var predecessor = [];

    var _loop = function _loop() {
      var mini = Number.POSITIVE_INFINITY;
      var s1 = -1;

      Q.forEach(function (s) {
        if (s1 == -1 || d[s] < mini) {
          mini = d[s];
          s1 = s;
        }
      });

      Q.splice(Q.indexOf(s1), 1);

      for (var s2 in A[s1]) {
        if (d[s2] > d[s1] + A[s1][s2]) {
          d[s2] = d[s1] + A[s1][s2];
          predecessor[s2] = s1;
        }
      }
    };

    while (Q.length > 0) {
      _loop();
    }

    return predecessor;
  },
  getPath: function getPath(predecessor, sDeb, sEnd) {
    var A = [];
    var s = sEnd;

    while (s != sDeb) {
      A.push(s);
      s = predecessor[s];
    }

    A.push(sDeb);
    return A.reverse();
  },
  getWeight: function getWeight(edgeMap, path) {
    var weight = 0;
    var vertex = undefined;

    path.forEach(function (v) {
      if (vertex != undefined) weight += edgeMap[vertex][v];
      vertex = v;
    });

    return weight;
  }
};