[JavaScript] Tree, 너비 우선 탐색 BFS, 깊이 우선 탐색 DFS

Task

--- Directions

1. Create a node class. The constructor
   should accept an argument that gets assigned
   to the data property and initialize an
   empty array for storing children. The node
   class should have methods 'add' and 'remove'.

2. Create a tree class. The tree constructor
   should initialize a 'root' property to null.

3. Implement 'traverseBF' and 'traverseDF'
   on the tree class. Each method should accept a
   function that gets called with each element in the tree

Solution

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

  add(data) {
    this.children.push(new Node(data));
  }

  remove(data) {
    this.children = this.children.filter(node => {
      return node.data !== data;
    });
  }
}

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

  traverseBF(fn) {
    const arr = [this.root];

    while (arr.length) {
      const node = arr.shift();

      arr.push(...node.children);
      fn(node);
    }
  }

  traverseDF(fn) {
    const arr = [this.root];

    while (arr.length) {
      const node = arr.shift();

      arr.unshift(...node.children);
      fn(node);
    }
  }
}