11_tree_level_order.js

/*
Given a tree, write a function that prints out the nodes of the tree in level order.

tree : 
        1
      /   \
     2     3
    / \   / \
   4   5 6   7
   
   traverse(tree) ->  1 2 3 4 5 6 7 
*/

class Node {
    constructor(value) {
        this.value = value;
        this.left = null;
        this.right = null;
    }
}

function traverse(tree) {
    if (!tree) return;

    const queue = [];
    queue.push(tree);

    while (queue.length > 0) {
        let curr = queue.shift();
        console.log(curr.value);

        if (curr.left !== null) queue.push(curr.left);
        if (curr.right !== null) queue.push(curr.right);
    }
}

let left = new Node(2);
left.left = new Node(4);
left.right = new Node(5);

let right = new Node(3);
right.left = new Node(6);
right.right = new Node(7);

let tree = new Node(1);
tree.left = left;
tree.right = right;

traverse(tree);