Floyd–Warshall algorithm

function Floyd(roads) {
  var M = {};
  for (var i in roads) {
    M[i] = {};
    for (var j in roads) {
      M[i][j] = distance(i, j);
    }
  }
  for (var p in roads) {
    for (var q in roads) {
      for (var r in roads) {
        M[q][r] = Math.min(M[q][r], M[q][p] + M[p][r]);
      }
    }
  }
  return M;
}

var roads = {};
function makeRoad(from, to, length) {
  function addRoad(from, to) {
    if (!(from in roads))
      roads[from] = {};
    roads[from][to] = length;
  }
  addRoad(from, to);
  addRoad(to, from);
}

function makeRoads(start) {
  for (var i = 1; i < arguments.length; i += 2)
    makeRoad(start, arguments[i], arguments[i + 1]);
}

// Direct distance.
function distance(from, to) {
  if (from === to) {
    return 0;
  }
  if (roads[from][to] !== undefined) {
    return roads[from][to];
  }
  return Number.POSITIVE_INFINITY;
}



makeRoads("A", "B", 2, "C", 3);
makeRoads("B", "C", 3, "D", 6);
makeRoads("C", "D", 3, "E", 5);
makeRoads("D", "E", 1, "F", 3);
makeRoads("E", "F", 1);



function init() {
  var s = 'A--2-B--6-D--3-F \n';
  s = s + ' \\   |   /|   / \n';
  s = s + '  3  3  3 1  1   \n';
  s = s + '   \\ | /  | /   \n';
  s = s + '     C--5-E      \n';
  print(s, "pre");
}

init();
var res = Floyd(roads);
printLn('Distance A --> F: ' + res.A.F);
printLn('Distance B --> E: ' + res.B.E);