add node and edge for the graph

Author: chen0040

README.md

@@ -29,7 +29,7 @@ The sample code below shows how to create a undirected and unweighted graph:
 ```javascript
 var jsgraphs = require('js-graph-algorithms');
 
-var g = new jsgraphs.Graph(6);
+var g = new jsgraphs.Graph(6); // 6 is the number vertices in the graph
 g.addEdge(0, 5); // add undirected edge connecting vertex 0 to vertex 5
 g.addEdge(2, 4);
 g.addEdge(2, 3);
@@ -39,6 +39,9 @@ g.addEdge(3, 4);
 g.addEdge(3, 5);
 g.addEdge(0, 2);
 
+g.node(2).label = 'Hello'; // assigned 'Hello' as label for node 2
+g.edge(0, 2).label = 'World'; // edge between 0 and 2
+
 console.log(g.V); // display 6, which is the number of vertices in g
 console.log(g.adj(0)); // display [5, 1, 2], which is the adjacent list to vertex 0
 ```
@@ -50,7 +53,7 @@ The sample code below shows how to create a direted and unweighted graph:
 ```javascript
 var jsgraphs = require('js-graph-algorithms');
 
-var g = new jsgraphs.DiGraph(13);
+var g = new jsgraphs.DiGraph(13); // 13 is the number vertices in the graph
 g.addEdge(4,  2); // add directed edge from 4 to 2
 g.addEdge(2,  3);
 g.addEdge(3,  2);
@@ -74,6 +77,9 @@ g.addEdge(6,  4);
 g.addEdge(6,  9);
 g.addEdge(7,  6);
 
+g.node(2).label = 'Hello'; // assign 'Hello' as label for node 2
+g.edge(0, 5).label = 'World'; // edge from 0 to 5
+
 console.log(g.V); // display 13, which is the number of vertices in g
 console.log(g.adj(0)); // display the adjacency list which are vertices directed from vertex 0
 ```
@@ -84,7 +90,7 @@ The sample code below shows show to create undirected weighted graph:
 
 ```javascript
 var jsgraphs = require('js-graph-algorithms');
-var g = new jsgraphs.WeightedGraph(8);
+var g = new jsgraphs.WeightedGraph(8); // 8 is the number vertices in the graph
 g.addEdge(new jsgraphs.Edge(0, 7, 0.16));
 g.addEdge(new jsgraphs.Edge(2, 3, 0.17));
 g.addEdge(new jsgraphs.Edge(1, 7, 0.19));
@@ -102,6 +108,9 @@ g.addEdge(new jsgraphs.Edge(3, 6, 0.52));
 g.addEdge(new jsgraphs.Edge(6, 0, 0.58));
 g.addEdge(new jsgraphs.Edge(6, 4, 0.93));
 
+g.node(2).label = 'Hello'; // assign 'Hello' as label for node 2
+g.edge(4, 5).label = 'World'; // edge between node 4 and 5
+
 console.log(g.V); // display 13, which is the number of vertices in g
 console.log(g.adj(0)); // display the adjacency list which are undirected edges connected to vertex 0
 ```
@@ -112,7 +121,7 @@ The sample code below shows show to create directed weighted graph:
 
 ```javascript
 var jsgraphs = require('js-graph-algorithms');
-var g = new jsgraphs.WeightedDiGraph(8);
+var g = new jsgraphs.WeightedDiGraph(8); // 8 is the number vertices in the graph
 g.addEdge(new jsgraphs.Edge(0, 7, 0.16));
 g.addEdge(new jsgraphs.Edge(2, 3, 0.17));
 g.addEdge(new jsgraphs.Edge(1, 7, 0.19));
@@ -130,6 +139,9 @@ g.addEdge(new jsgraphs.Edge(3, 6, 0.52));
 g.addEdge(new jsgraphs.Edge(6, 0, 0.58));
 g.addEdge(new jsgraphs.Edge(6, 4, 0.93));
 
+g.node(2).label = 'Hello';
+g.edge(4, 5).label = 'World'; // edge from node 4 to node 5
+
 console.log(g.V); // display 13, which is the number of vertices in g
 console.log(g.adj(0)); // display the adjacency list which are directed edges from vertex 0
 ```

examples/example-graph.html

@@ -4,6 +4,7 @@
             Graph
         </title>
         <script src="../third-party-libs/vis/vis.js" type="text/javascript"></script>
+        <script src="../src/jsgraphs.js" type="text/javascript"></script>
         <link href="../third-party-libs/vis/vis.css" type="text/css" />
     </head>
 

src/jsgraphs.js

@@ -345,38 +345,79 @@ var jsgraphs = jsgraphs || {};
 	var Graph = function (V) {
         this.V = V;
         this.adjList = [];
+        this.nodeInfo = [];
+        this.edges = {};
         for (var i = 0; i < V; ++i) {
             this.adjList.push([]);
+            this.nodeInfo.push({});
         }
     };
 
     Graph.prototype.addEdge = function(v, w){
         this.adjList[v].push(w);
         this.adjList[w].push(v);
+        var edge_id = v + '_' + w;
+        if(v > w) {
+            edge_id = w + '_' + v;
+        }
+        this.edges[edge_id] = new jss.Edge(v, w, 0);
     };
 
     Graph.prototype.adj = function(v) {
         return this.adjList[v];  
     };
 
+    Graph.prototype.node = function(v) {
+        return this.nodeInfo[v];  
+    };
+    
+    Graph.prototype.edge = function(v, w) {
+        var edge_id = v + '_' + w;
+        if(v > w) {
+            edge_id = w + '_' + v;
+        }
+        if (edge_id in this.edges) {
+            return this.edges[edge_id];
+        }
+        return null;
+    };
+    
     jss.Graph = Graph;
 
     var DiGraph = function(V) {
         this.V = V;
         this.adjList = [];
+        this.nodeInfo = [];
+        this.edges = {};
         for (var v = 0; v < V; ++v){
             this.adjList.push([]);
+            this.nodeInfo.push({});
         }
     };
 
     DiGraph.prototype.addEdge = function(v, w){
         this.adjList[v].push(w);
+        var edge_id = v + '_' + w;
+        this.edges[edge_id] = new jss.Edge(v, w, 0);
+    };
+    
+    DiGraph.prototype.edge = function(v, w) {
+        var edge_id = v + '_' + w;
+        if(edge_id in this.edges) {
+            return this.edges[edge_id];
+        } else {
+            return null;
+        }
     };
 
     DiGraph.prototype.adj = function(v) {
         return this.adjList[v];  
     };
 
+    DiGraph.prototype.node = function(v) {
+        return this.nodeInfo[v];  
+    };
+    
     DiGraph.prototype.reverse = function(){
         var g = new DiGraph(this.V);
         for (var v = 0; v < this.V; ++v) {
@@ -418,16 +459,33 @@ var jsgraphs = jsgraphs || {};
     var WeightedGraph = function(V) {
         this.V = V;
         this.adjList = [];
+        this.nodeInfo = [];
 
         for ( var v = 0; v < V; ++v) {
             this.adjList.push([]);
+            this.nodeInfo.push({});
         }
     };
 
     WeightedGraph.prototype.adj = function(v) {
         return this.adjList[v];  
     };
 
+    WeightedGraph.prototype.edge = function(v, w) {
+        var adj_v = this.adjList[v];
+        for(var i=0; i < adj_v.length; ++i) {
+            var x = adj_v[i].other(v);
+            if(x == w) {
+                return adj_v[i];
+            }
+        }
+        return null;
+    };
+    
+    WeightedGraph.prototype.node = function(v) {
+        return this.nodeInfo[v];  
+    };
+    
     WeightedGraph.prototype.addEdge = function(e) {
         var v = e.either();
         var w = e.other(v);
@@ -448,6 +506,17 @@ var jsgraphs = jsgraphs || {};
         this.adjList[v].push(e);
     };
 
+    WeightedDiGraph.prototype.edge = function(v, w) {
+        var adj_v = this.adjList[v];
+        for(var i=0; i < adj_v.length; ++i) {
+            var x = adj_v[i].other(v);
+            if(x == w) {
+                return adj_v[i];
+            }
+        }
+        return null;
+    };
+    
     WeightedDiGraph.prototype.toDiGraph = function() {
         var g = new jss.DiGraph(this.V);
         for(var v = 0; v < this.V; ++v) {

test/directed-graph-spec.js

@@ -26,6 +26,8 @@ describe("Create various types of DiGraph", function() {
     g.addEdge(6,  4);
     g.addEdge(6,  9);
     g.addEdge(7,  6);
+      
+    g.edge(2, 0).label = 'World';
     it("should has 13 vertices", function() {
     	expect(g.V).to.equal(13); 
     });

test/graph-spec.js

@@ -12,6 +12,7 @@ describe("Create various types of Graphs", function() {
     g.addEdge(3, 4);
     g.addEdge(3, 5);
     g.addEdge(0, 2);
+    g.node(2).label = 'Hello';
     it("should has 6 vertices", function() {
     	expect(g.V).to.equal(6); 
     });

test/weighted-digraph-spec.js

@@ -21,6 +21,9 @@ describe('Weigthed Directed Graph', function(){
         g.addEdge(new jsgraphs.Edge(7, 5, 6.0));
         g.addEdge(new jsgraphs.Edge(7, 2, 7.0));  
 
+        g.node(4).label = 'Hello';
+        g.edge(4, 5).label = 'World';
+       
         expect(g.V).to.equal(8);
         var edgeCount = 0;
         for(var v = 0; v < g.V; ++v){

test/weighted-graph-spec.js

@@ -20,6 +20,10 @@ describe("Create various types of Weighted Graphs", function() {
     g.addEdge(new jsgraphs.Edge(3, 6, 0.52));
     g.addEdge(new jsgraphs.Edge(6, 0, 0.58));
     g.addEdge(new jsgraphs.Edge(6, 4, 0.93));
+      
+    g.node(4).label = 'Hello';
+    g.edge(4, 5).label = 'World';
+      
     it("should has 8 vertices", function() {
     	expect(g.V).to.equal(8); 
     });