string_interview_Questions.html

<script>
  function Node(data) {
    this.data = data;
    this.children = [];
  }

  class Tree {
    constructor() {
      this.root = null;
    }

    add(data, toNodeData) {
      const node = new Node(data);
      // console.warn(node)
      // If the toNodeData arg is passed, find it. Otherwise, store null.
      const parent = toNodeData ? this.findBFS(toNodeData) : null;

      // Push new node to parent whose value matches toNodeData
      if (parent) {
        parent.children.push(node);
      } else {
        // If there's no parent, make this the root node
        if (!this.root) this.root = node;
        else return "Tried to store node as root when root already exists.";
      }
    }

    findBFS(data) {
      const queue = [this.root];
      let _node = null;

      // Go thru every node in BFS
      this.traverseBFS((node) => {
        // Return match if found
        if (node.data === data) {
          _node = node;
        }
      });

      return _node;
    }

    traverseBFS(cb) {
      const queue = [this.root];

      if (cb)
        while (queue.length) {
          // Store current node & remove it from queue
          const node = queue.shift();

          cb(node);

          // Push children of current node to end of queue
          for (const child of node.children) {
            queue.push(child);
          }
        }
    }
  }

  (function test() {
    let tree = new Tree();

    tree.add("root");
    tree.add("Node2", "Node1");
    tree.add("Node3", "Node1");

    console.log(tree);

    tree.traverseBFS((node) => {
      console.log(node);
    });
  })();
</script>