Kth Smallest Element in a BST

<aside> 💡 Do a DFS inorder. Get Kth element from the visited array.

</aside>

https://leetcode.com/problems/kth-smallest-element-in-a-bst/

function dfs(node) {
  if (!node) return;
  visited.push(node.val);
  dfs(node.left);
  dfs(node.right);
}

• Solution

Invert Binary Tree

<aside> 💡 Run a DFS. Swap left and right.

</aside>

https://leetcode.com/problems/invert-binary-tree/

function dfs(node) {

  if (!node) {
    return null;
  }

  [node.left, node.right] = [node.right, node.left];

  dfs(node.left);
  dfs(node.right);

}

• Solution

Same tree