Write The Shortest Program to Calculate Height of a Binary Tree The height of a binary tree is the distance from the root node to the node child that is farthest from the root.

Below is an example:

           2 &lt;-- root: Height 1
          / \
         7   5 &lt;-- Height 2
        / \   \
       2   6   9 &lt;-- Height 3
          / \  /
         5  11 4 &lt;-- Height 4 


Height of binary tree: 4

Definition of a Binary Tree

A tree is an object that contains a signed integer value and either two other trees or pointers to them.

The structure of the binary tree struct looks something like the following:

typedef struct tree
{
  struct tree * l;

  struct tree * r;

  int v;

} tree;


The challenge:

Input

The root of a binary tree

Output

The number that represents the height of a binary tree

Assuming you are given the root of a binary tree as input, write the shortest program that calculates the height of a binary tree and returns the height. The program with least amount of bytes (accounting whitespaces) wins.
Jelly, 3 bytes

ŒḊ’


A monadic Link accepting a list representing the tree: [root_value, left_tree, right_tree], where each of left_tree and right_tree are similar structures (empty if need be), which yields the height.

Try it online!

How?

Pretty trivial in Jelly:

ŒḊ’ - Link: list, as described above
ŒḊ  - depth
  ’ - decremented (since leaves are `[value, [], []]`)