From 00842023406e0c55dd438621045e41f28cac6aca Mon Sep 17 00:00:00 2001
From: Anna Yasenova <yasenova2013@gmail.com>
Date: Tue, 14 Mar 2017 00:20:02 +0200
Subject: [PATCH] Simple implementation of undirected graph.

---
 undirected.js | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 undirected.js

diff --git a/undirected.js b/undirected.js
new file mode 100644
index 0000000..ff7de68
--- /dev/null
+++ b/undirected.js
@@ -0,0 +1,90 @@
+'use strict';
+
+class Graph {
+
+    constructor() {
+        this.vertex = [];
+        this.edge = [];
+        this.edgeCounter = 0;
+    }
+
+    addVert(vertex) {
+        this.vertex.push(vertex);
+        this.edge[vertex] = []; //all edges
+    }
+
+    addEdge(nodeFrom, nodeTo) {
+        this.edgeCounter++;
+        this.edge[nodeFrom].push(nodeTo);
+        this.edge[nodeTo].push(nodeFrom); //undirected!
+    }
+
+	//returns size of graph
+    vertexNumber() {
+        return this.vertex.length;
+    }
+
+    edgeNumber() {
+        return this.edgeCounter;
+    }
+
+    rmVert(vert) {
+        const pos = this.vertex.indexOf(vert);
+        if(pos !== -1) {
+            this.vertex.splice(pos, 1);
+        }
+        while (this.edge[vert].length) {
+            const second = this.edge[vert].pop();
+            this.rmEdge(second, vert);
+        }
+    }
+
+    rmEdge(nodeFrom, nodeTo) {
+        const pos1 = this.edge[nodeFrom] ? this.edge[nodeFrom].indexOf(nodeTo) : -1;
+        const pos2 = this.edge[nodeTo] ? this.edge[nodeTo].indexOf(nodeFrom) : -1;
+        if(pos1 !== -1) {
+            this.edge[nodeFrom].splice(pos1, 1);
+            this.edgeCounter--;
+        }
+        if(pos2 !== -1) {
+            this.edge[nodeTo].splice(pos2, 1);
+        }
+    }
+
+    output() {
+        let i;
+        for(i of this.vertex) {
+            console.dir('Vertex: ' + i);
+            let j;
+            for (j of this.edge[i]) {
+                console.dir('Edge: ' + j);
+            }
+        }
+
+        console.dir('Graph has ' + this.vertexNumber() + ' nodes');
+        console.dir('Graph has ' + this.edgeNumber() + ' edges');
+    }
+
+}
+
+const graph = new Graph();
+graph.addVert('first');
+graph.addVert('second');
+graph.addVert('third');
+graph.addVert('fourth');
+graph.addVert('fifth');
+graph.addVert('sixth');
+graph.output();
+graph.addEdge('first', 'second');
+graph.addEdge('first', 'fifth');
+graph.addEdge('fourth', 'fifth');
+graph.addEdge('fifth', 'second');
+graph.addEdge('third', 'fourth');
+graph.addEdge('second', 'third');
+graph.addEdge('fourth', 'sixth');
+graph.output();
+graph.rmEdge('first', 'second');
+graph.rmEdge('fourth', 'fifth');
+graph.rmEdge('something', '????');
+graph.rmVert('fifth');
+graph.output();
\ No newline at end of file