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Graph.ts
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Graph.ts
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class Vertex {
label: string;
adjacencyList: [];
constructor(label) {
this.label = label;
this.adjacencyList = [];
}
}
class Graph {
map = {};
addNode(label: string) {
const vertex = new Vertex(label);
if (!this.map[label]) this.map[label] = vertex;
}
addEdge(from: string, to: string) {
if (from === to) return;
// check if the vertex exsit
if (!this.map[from] || !this.map[to]) return false;
this.map[from].adjacencyList.push(to);
}
print() {
for (const node in this.map) {
if (Object.prototype.hasOwnProperty.call(this.map, node)) {
console.log(
`${node} is Connected with [${this.map[
node
].adjacencyList.toString()}]`
);
}
}
}
removeNode(label: string) {
if (!this.map[label]) return false;
delete this.map[label];
for (let n in this.map) {
let adjacencyList = this.map[n].adjacencyList;
const idx = adjacencyList.indexOf(label);
adjacencyList.splice(idx, 1);
}
}
removeEdge(from: string, to: string) {
if (from == to) return;
if (!this.map[from] || !this.map[from]) return;
let adjacencyList = this.map[from].adjacencyList;
let idx = adjacencyList.indexOf(to);
if (idx === -1) return false;
adjacencyList.splice(idx, 1);
return true;
}
DepthFirstTraversal(root) {
let node = this.map[root];
if (!node) return;
const set = new Set();
this._DepthFirstTraversal(node, set);
console.log(set);
return set;
}
_DepthFirstTraversal(node, set) {
set.add(node.label);
let adjacencyList = node.adjacencyList;
if (adjacencyList.length === 0 || !node || set.has(adjacencyList[0]))
return;
let nextNode = this.map[adjacencyList[0]];
this._DepthFirstTraversal(nextNode, set);
}
DepthStack(root) {
let node = this.map[root];
if (!node) return;
let stack = [];
let visited = new Set();
stack.push(node);
while (stack.length > 0) {
let current = stack.pop();
visited.add(current.label);
for (const node of current.adjacencyList) {
if (visited.has(node)) continue;
stack.push(this.map[node]);
}
}
console.log(visited);
return visited;
}
BreathFirstSearch(root) {
let node = this.map[root];
if (node == null) return;
let visited = new Set();
let queue = [];
queue.push(node);
while (queue.length > 0) {
let current = queue.shift();
visited.add(current.label);
for (let n of current.adjacencyList) {
if (visited.has(n)) continue;
let nextNode = this.map[n];
queue.push(nextNode);
}
}
console.log(visited);
return visited;
}
topologicalSorting() {
let visited = new Set();
let stack = [];
for (let n in this.map) {
this._topologicalSorting(this.map[n], visited, stack);
}
let sorted = [];
while (stack.length > 0) {
sorted.push(stack.pop());
}
return sorted;
}
_topologicalSorting(node: Vertex, visited: any, stack: string[]) {
if (visited.has(node.label)) return;
visited.add(node.label);
let adjacencyList = node.adjacencyList;
for (let n in adjacencyList) {
this._topologicalSorting(this.map[adjacencyList[n]], visited, stack);
}
// we are in the very end
stack.push(node.label);
}
hasCycle() {
let visiting = new Set();
let visited = new Set();
for (let n in this.map) {
const isCycle = this._hasCycle(this.map[n], visiting, visited);
if (isCycle) return true;
}
console.log(visited);
console.log(visiting);
return false;
}
_hasCycle(node: Vertex, visiting, visited) {
visiting.add(node.label);
let adjacencyList = node.adjacencyList;
for (let n of adjacencyList) {
if (visited.has(n)) continue;
if (visiting.has(n)) return true;
if (this._hasCycle(this.map[n], visiting, visited)) return true;
}
visited.add(node.label);
visiting.delete(node.label);
return false;
}
}
const graph = new Graph();
graph.addNode('A');
graph.addNode('B');
graph.addNode('C');
graph.addEdge('A', 'B');
graph.addEdge('B', 'C');
graph.addEdge('C', 'A');
// graph.removeNode('Jone');
// console.log(graph.removeEdge('Jone', 'Doe'));
// graph.DepthFirstTraversal('C');
// graph.DepthStack('A');
// graph.BreathFirstSearch('A');
// graph.topologicalSorting();
console.log(graph.hasCycle());
// graph.print();
// console.log(graph);