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import { TreeNode } from "../binary-tree-inorder-traversal/TreeNode.ts";
export default function countNodes(    root: TreeNode | null,    leftDepth?: number,    rightDepth?: number,): number {    if (root === null) return 0;    let left = 0,        right = 0;    let curNode: TreeNode | null = root;    if (typeof leftDepth !== "undefined") {        left = leftDepth;    } else {        while (curNode !== null) {            left++;            curNode = curNode.left;        }    }
    curNode = root;    if (typeof rightDepth !== "undefined") {        right = rightDepth;    } else {        while (curNode !== null) {            right++;            curNode = curNode.right;        }    }    if (left === right) {        return 2 ** left - 1;    }    return (        1 +        countNodes(root.left, left - 1) +        countNodes(root.right, undefined, right - 1)    );}