find path to a node

path.js

  class Node  {
	constructor(value) {
		this.value = value;
		this.children = [];
	}

	add(child) {
		this.children.push(child);
	}

	print(level=0) {
		let indent = "";
		for (let i = 0; i < level * 2; i++) {
			indent += " ";
		}
		process.stdout.write(`${indent}value : ${this.value} \n`);

		if(this.children.length > 0) {
			process.stdout.write(`${indent}children ↓↓ \n`);
			this.children.forEach(child => {
				child.print(level+1);
			});
		}

	}

	printPath(value) {
		let path = [];
		if (this.hasPath(value, path)) {
			return path.map(step => step.value).join(" -> ");
		} else {
			return "No Path Found";
		}
	}

	hasPath(value, opt_path) {
		let path = opt_path || [];

		function hasPathImpl(node, value, path) {
			if (!node) {
				return false;
			}
			path.push(node);
			if (node.value == value) {
				return true;
			}

			let bool = false;
			for(let i = 0; i < node.children.length; i++) {
				bool = bool || hasPathImpl(node.children[i], value, path);
			}

			if (bool) { return true; }

			path.pop();
			return false;
		}

		return hasPathImpl(this, value, path);
	}

	
	
}

function p(o) {
	console.log(o);
}

let root = new Node(0);

let l1 = new Node(10);
let l2 = new Node(100);
let l3 = new Node(500);

root.add(l1);
root.add(l2);
root.add(l3);

let p1 = new Node('A');
let p2 = new Node('B');

l1.add(p1);
l1.add(p2);

let x1 = new Node('X');
l3.add(x1);

let z1 = new Node("horse");
let z2 = new Node("rabbit");
x1.add(z1);
x1.add(z2);

p(root.hasPath(16));
p(root.hasPath('horse'));
p(root.hasPath('rabbit'));

p(root.printPath(16));
p(root.printPath('horse'));
p(root.printPath('rabbit'));

false
true
true
No Path Found
0 -> 500 -> X -> horse
0 -> 500 -> X -> rabbit
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