cassidoo algo practice - Write a data structure for a simple binary tree, and a function that prints a given tree.

printBinaryTree.js

class Node {
  value = null;
  left = null;
  right = null;

  constructor(value) {
    this.value = value;
  }

  printBothNodes(right, left, lastNodeVal) {
    const { value: leftVal } = left;
    const { value: rightVal } = right;
    let toPrint = "";
    Array(lastNodeVal - 1)
      .fill(null)
      .forEach(() => {
        toPrint += " ";
      });
    console.log(`${toPrint}${leftVal}   ${rightVal}`);

    this.printNodes(left, lastNodeVal - 1, true);
    this.printNodes(right, lastNodeVal - 1, true);
  }

  printNodes(node, lastNodeVal, isDeep) {
    const { value, left, right } = node ?? {};
    // leaf nodes
    if (left === null && right === null) {
      return;
    }
    // has both nodes
    if (left !== null && right !== null) {
      if (!isDeep) {
        // root
        let toPrint = "";
        Array(lastNodeVal)
          .fill(null)
          .forEach(() => {
            toPrint += " ";
          });
        toPrint += value;
        console.log(toPrint);
      }

      // print branches
      let toPrintBranch = "";
      Array(lastNodeVal - 1)
        .fill(null)
        .forEach(() => {
          toPrintBranch += " ";
        });
      console.log((toPrintBranch += "/ \\"));
      this.printBothNodes(right, left, lastNodeVal - 1);
      return;
    }
  }
}

let root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.left.right = new Node(5);

root.printNodes(root, 5);