Coding Challenge Practice - Question 55

The task is to invert a binary tree

function invert(node) {
  // your code here
}

To invert a binary tree means to invert the left and right child of every node. Do this for every node in the binary tree.

If there are no nodes, return null

if(!node) return null;

Store the left child in a temp variable, assign it to the right child and the right child to the left child.

const temp = node.left;
node.left = node.right;
node.right = temp;

Then, invert the left subtree and the right subtree

invert(node.left);
invert(node.right);

The final code

function invert(node) {
  // your code here
  if(!node) return null;

  const temp = node.left
  node.left = node.right
  node.right = temp

  invert(node.left);
  invert(node.right);

  return node;
}

That's all folks!