Search in BST

 class Solution {
 public:
    TreeNode* searchBST(TreeNode* root, int val) {
        if(root == nullptr) return nullptr;
        if( root->val == val)
            return root;
        else{
            if(val < root->val) return searchBST(root->left, val);
            else return searchBST(root->right, val);
        }
       return NULL;
    }
 };