Javascript Data Structure Graph (2)

function Stack() {

    let items = [];

    this.push = function(element){
        items.push(element);//from  w  ww .  j a v a2s  . c om
    };

    this.pop = function(){
        return items.pop();
    };

    this.peek = function(){
        return items[items.length-1];
    };

    this.isEmpty = function(){
        return items.length == 0;
    };

    this.size = function(){
        return items.length;
    };

    this.clear = function(){
        items = [];
    };

    this.print = function(){
        console.log(items.toString());
    };

    this.toString = function(){
        return items.toString();
    };
}

function Queue() {

    let items = [];

    this.enqueue = function(element){
        items.push(element);
    };

    this.dequeue = function(){
        return items.shift();
    };

    this.front = function(){
        return items[0];
    };

    this.isEmpty = function(){
        return items.length == 0;
    };

    this.clear = function(){
        items = [];
    };

    this.size = function(){
        return items.length;
    };

    this.print = function(){
        console.log(items.toString());
    };
}

function Dictionary(){

    var items = {};

    this.set = function(key, value){
        items[key] = value; //{1}
    };

    this.delete = function(key){
        if (this.has(key)){
            delete items[key];
            return true;
        }
        return false;
    };

    this.has = function(key){
        return items.hasOwnProperty(key);
        //return value in items;
    };

    this.get = function(key) {
        return this.has(key) ? items[key] : undefined;
    };

    this.clear = function(){
        items = {};
    };

    this.size = function(){
        return Object.keys(items).length;
    };

    this.keys = function(){
        return Object.keys(items);
    };

    this.values = function(){
        var values = [];
        for (var k in items) {
            if (this.has(k)) {
                values.push(items[k]);
            }
        }
        return values;
    };

    this.each = function(fn) {
        for (var k in items) {
            if (this.has(k)) {
                fn(k, items[k]);
            }
        }
    };

    this.getItems = function(){
        return items;
    }
}


function Graph() {

    var vertices = []; //list

    var adjList = new Dictionary();

    this.addVertex = function(v){
        vertices.push(v);
        adjList.set(v, []); //initialize adjacency list with array as well;
    };

    this.addEdge = function(v, w){
        adjList.get(v).push(w);
        //adjList.get(w).push(v); //commented to run the improved DFS with topological sorting
    };

    this.toString = function(){
        var s = '';
        for (var i=0; i<vertices.length; i++){
            s += vertices[i] + ' -> ';
            var neighbors = adjList.get(vertices[i]);
            for (var j=0; j<neighbors.length; j++){
                s += neighbors[j] + ' ';
            }
            s += '\n';
        }
        return s;
    };

    var initializeColor = function(){
        var color = {};
        for (var i=0; i<vertices.length; i++){
            color[vertices[i]] = 'white';
        }
        return color;
    };

    this.bfs = function(v, callback){

        var color = initializeColor(),
            queue = new Queue();
        queue.enqueue(v);

        while (!queue.isEmpty()){
            var u = queue.dequeue(),
                neighbors = adjList.get(u);
            color[u] = 'grey';
            for (var i=0; i<neighbors.length; i++){
                var w = neighbors[i];
                if (color[w] === 'white'){
                    color[w] = 'grey';
                    queue.enqueue(w);
                }
            }
            color[u] = 'black';
            if (callback) {
                callback(u);
            }
        }
    };

    this.dfs = function(callback){

        var color = initializeColor();

        for (var i=0; i<vertices.length; i++){
            if (color[vertices[i]] === 'white'){
                dfsVisit(vertices[i], color, callback);
            }
        }
    };

    var dfsVisit = function(u, color, callback){

        color[u] = 'grey';
        if (callback) {
            callback(u);
        }
        console.log('Discovered ' + u);
        var neighbors = adjList.get(u);
        for (var i=0; i<neighbors.length; i++){
            var w = neighbors[i];
            if (color[w] === 'white'){
                dfsVisit(w, color, callback);
            }
        }
        color[u] = 'black';
        console.log('explored ' + u);
    };


    this.BFS = function(v){

        var color = initializeColor(),
            queue = new Queue(),
            d = {},
            pred = {};
        queue.enqueue(v);

        for (var i=0; i<vertices.length; i++){
            d[vertices[i]] = 0;
            pred[vertices[i]] = null;
        }

        while (!queue.isEmpty()){
            var u = queue.dequeue(),
                neighbors = adjList.get(u);
            color[u] = 'grey';
            for (i=0; i<neighbors.length; i++){
                var w = neighbors[i];
                if (color[w] === 'white'){
                    color[w] = 'grey';
                    d[w] = d[u] + 1;
                    pred[w] = u;
                    queue.enqueue(w);
                }
            }
            color[u] = 'black';
        }

        return {
            distances: d,
            predecessors: pred
        };
    };

    var time = 0;
    this.DFS = function(){

        var color = initializeColor(),
            d = {},
            f = {},
            p = {};
        time = 0;

        for (var i=0; i<vertices.length; i++){
            f[vertices[i]] = 0;
            d[vertices[i]] = 0;
            p[vertices[i]] = null;
        }

        for (i=0; i<vertices.length; i++){
            if (color[vertices[i]] === 'white'){
                DFSVisit(vertices[i], color, d, f, p);
            }
        }

        return {
            discovery: d,
            finished: f,
            predecessors: p
        };
    };

    var DFSVisit = function(u, color, d, f, p){

        console.log('discovered ' + u);
        color[u] = 'grey';
        d[u] = ++time;
        var neighbors = adjList.get(u);
        for (var i=0; i<neighbors.length; i++){
            var w = neighbors[i];
            if (color[w] === 'white'){
                p[w] = u;
                DFSVisit(w,color, d, f, p);
            }
        }
        color[u] = 'black';
        f[u] = ++time;
        console.log('explored ' + u);
    };
}
var graph = new Graph();

var myVertices = ['A','B','C','D','E','F','G','H','I'];

for (var i=0; i<myVertices.length; i++){
    graph.addVertex(myVertices[i]);
}
graph.addEdge('A', 'B');
graph.addEdge('A', 'C');
graph.addEdge('A', 'D');
graph.addEdge('C', 'D');
graph.addEdge('C', 'G');
graph.addEdge('D', 'G');
graph.addEdge('D', 'H');
graph.addEdge('B', 'E');
graph.addEdge('B', 'F');
graph.addEdge('E', 'I');

console.log('********* printing graph ***********');

console.log(graph.toString());

console.log('********* bfs ***********');

function printNode(value){
    console.log('Visited vertex: ' + value);
}

graph.bfs(myVertices[0], printNode);

console.log('********* dfs ***********');

graph.dfs();

console.log('********* sorthest path - BFS ***********');
var shortestPathA = graph.BFS(myVertices[0]);
console.log(shortestPathA.distances);
console.log(shortestPathA.predecessors);

//from A to all other vertices
var fromVertex = myVertices[0];

for (i=1; i<myVertices.length; i++){
    var toVertex = myVertices[i],
        path = new Stack();
    for (var v=toVertex; v!== fromVertex; v=shortestPathA.predecessors[v]) {
        path.push(v);
    }
    path.push(fromVertex);
    var s = path.pop();
    while (!path.isEmpty()){
        s += ' - ' + path.pop();
    }
    console.log(s);
}

console.log('********* topological sort - DFS ***********');

//var result = graph.DFS();
//console.log(result.discovery);
//console.log(result.finished);
//console.log(result.predecessors);

graph = new Graph();

myVertices = ['A','B','C','D','E','F'];
for (i=0; i<myVertices.length; i++){
    graph.addVertex(myVertices[i]);
}
graph.addEdge('A', 'C');
graph.addEdge('A', 'D');
graph.addEdge('B', 'D');
graph.addEdge('B', 'E');
graph.addEdge('C', 'F');
graph.addEdge('F', 'E');


var result = graph.DFS();
console.log(result.discovery);
console.log(result.finished);
console.log(result.predecessors);

var fTimes = result.finished;
s = '';
for (var count=0; count<myVertices.length; count++){
    var max = 0;
    var maxName = null;
    for (i=0; i<myVertices.length; i++){
        if (fTimes[myVertices[i]] > max){
            max = fTimes[myVertices[i]];
            maxName = myVertices[i];
        }
    }
    s += ' - ' + maxName;
    delete fTimes[maxName];
}
console.log(s);