findLargestLevel.js

function Node(val){
  this.value = val;
  this.left = null;
  this.right = null;
}


function BinaryTree(){
  this.root = null;
}

BinaryTree.prototype.push = function(val){
   var root = this.root;

   if(!root){
      this.root = new Node(val);
      return;
   }

   var currentNode = root;
   var newNode = new Node(val);

   while(currentNode){
      if(val < currentNode.value){
          if(!currentNode.left){
             currentNode.left = newNode;
             break;
          }
          else{
             currentNode = currentNode.left;
        }
     }
     else{
         if(!currentNode.right){
            currentNode.right = newNode;
            break;
         }
         else{
            currentNode = currentNode.right;
         }
     }
  }

}

const findLargestLevel = function(node) {
  // your code here
  var largestLevel = [];

  if(node.root.right === null || node.root.left === null){
      return 0;
  }

  largestLevel.push(Math.max(findLargestLevel(node.root.left), findLargestLevel(node.root.right)));

  return largestLevel;
};





var root = new BinaryTree();
root.push(3);
root.push(2);
root.push(4);
root.push(1);
root.push(5);
root.push(3);
root.push(2);
root.push(4);
root.push(1);
root.push(5);

//console.log(root);
console.log(findLargestLevel(root));