Three questions in total, I tried searching the final two on LC but didn\'t find them\n\n- https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero/\n- Count visible nodes in binary tree -> there are many questions like this on google\n \n - Finding the lengths of the array -> an array represents a linked list where index 0 represents the head. Example [1,4,-1,3,2], result will be 4 where:\n\t\t - Head has value of 1\n\t\t - 1 has value of 4\n\t\t - 4 has value of 2\n\t\t - 2 has value of -1 which ends the LL

Three questions in total, I tried searching the final two on LC but didn\'t find them\n\n- https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero/\