JavaScript: Binary tree aggregation

In this test, we will use a binary tree, and perform data aggregation.

Node.js

Implement the following class methods:

• getCount() returns the number of nodes in the tree
• getSum() returns the sum of all tree keys
• toArray() returns a one-dimensional array containing all keys
• toString() returns a string representation of the tree
• every(fn) verifies that all tree keys meet the criteria stated in the passed function
• some(fn) verifies that at least one tree key meet the criteria stated in the passed function

Use the left-to-right order when traversing the tree. That is, first we process the node key, then the left child key, then the right child key.

Examples

const tree = new Node(9,
  new Node(4,
    new Node(8),
    new Node(6,
      new Node(3),
      new Node(7))),
  new Node(17,
    null,
    new Node(22,
      null,
      new Node(20))));

tree.getCount() // 9
tree.getSum(); // 96
tree.toArray(); // [9, 4, 8, 6, 3, 7, 17, 22, 20]
tree.toString(); // '(9, 4, 8, 6, 3, 7, 17, 22, 20)'

tree.every((key) => key <= 22); // true
tree.every((key) => key < 22); // false
tree.some((key) => key < 4); // true
tree.some((key) => key > 22); // false

Tips

• Binary tree
• To implement each of the methods, you will need to traverse all the tree nodes
• Recall the reduce array method