Graphs Complete Course

Author: HuXn-WebDev

8. Graphs/index.js

@@ -0,0 +1,81 @@
+class Graph {
+  constructor() {
+    this.adjacencyList = {};
+  }
+
+  addVertex(vtx) {
+    if (!this.adjacencyList[vtx]) {
+      this.adjacencyList[vtx] = [];
+      return true;
+    }
+    return false;
+  }
+
+  addEdge(vtx1, vtx2) {
+    if (this.adjacencyList[vtx1] && this.adjacencyList[vtx2]) {
+      this.adjacencyList[vtx1].push(vtx2);
+      this.adjacencyList[vtx2].push(vtx1);
+      return true;
+    }
+    return false;
+  }
+
+  removeEdge(vtx1, vtx2) {
+    if (this.adjacencyList[vtx1] && this.adjacencyList[vtx2]) {
+      this.adjacencyList[vtx1] = this.adjacencyList[vtx2].filter(
+        (v) => v !== vtx2
+      );
+
+      this.adjacencyList[vtx2] = this.adjacencyList[vtx2].filter(
+        (v) => v !== vtx1
+      );
+      return true;
+    }
+    return false;
+  }
+
+  removeVertex(vtx) {
+    if (!this.adjacencyList[vtx]) return undefined;
+
+    for (let neighbor of this.adjacencyList[vtx]) {
+      this.adjacencyList[neighbor] = this.adjacencyList[neighbor].filter(
+        (v) => v !== vtx
+      );
+    }
+
+    delete this.adjacencyList[vtx];
+    return this;
+  }
+}
+
+let g = new Graph();
+// ----------------
+// g.addVertex("A");
+// g.addVertex("B");
+// g.addEdge("A", "B");
+// ----------------
+
+// ----------------
+// g.addVertex("A");
+// g.addVertex("B");
+// g.addVertex("C");
+// g.addEdge("A", "B");
+// g.addEdge("B", "C");
+// g.addEdge("C", "A");
+// console.log(g);
+// g.removeEdge("A", "B");
+// console.log(g);
+// ----------------
+
+g.addVertex("A");
+g.addVertex("B");
+g.addVertex("C");
+g.addVertex("D");
+g.addEdge("A", "B");
+g.addEdge("A", "C");
+g.addEdge("A", "D");
+g.addEdge("B", "D");
+g.addEdge("C", "D");
+console.log(g);
+g.removeVertex("D");
+console.log(g);