Two Sum IV - Input is a BST

/** * Definition for a binary tree node. * function TreeNode(val, left, right) { *     this.val = (val===undefined ? 0 : val) *     this.left = (left===undefined ? null : left) *     this.right = (right===undefined ? null : right) * } *//** * @param {TreeNode} root * @param {number} k * @return {boolean} */var findTarget = function (root, k) {  // collecting all Element form BST  let allElements = [];  // inorder traversal becoz it will give sorted array for simplicity  function inOrderTraversal(root) {    if (root === null) {      return null;    }    inOrderTraversal(root.left);    allElements.push(root.val);    inOrderTraversal(root.right);  }  inOrderTraversal(root);  // creating map to keep track of all elements  let map = new Map();  allElements.forEach((element, index) => {    map.set(element, index);  });  // main loop to check if two values from array can give up the required sum  for (let i = 0; i < allElements.length; i++) {    let num = allElements[i];    let diff = k - num;    // checking if diff exist in map & also we have to make sure    // index of current element is not same as of matching element    if (map.has(diff) && map.get(diff) !== i) {      return true;    }  }  return false;};

/** * Definition for a binary tree node. * function TreeNode(val, left, right) { *     this.val = (val===undefined ? 0 : val) *     this.left = (left===undefined ? null : left) *     this.right = (right===undefined ? null : right) * } *//** * @param {TreeNode} root * @param {number} k * @return {boolean} */var findTarget = function(root, k) {     let map= new Map();    let bool=false;    const inorder =(root)=>{        if(root===null) return;        inorder(root.left);        if(map.has(k-root.val)){            bool=true;        }else{            map.set(root.val);        }        inorder(root.right);      }   inorder(root);   return bool;};