**Question 1:** https://leetcode.com/problems/valid-palindrome-ii/\nGiven a non-empty string s, you may delete at most one character. Judge whether you can make it a palindrome. \nI solved this question in 17 mins. They do not let you run the code so it\'s important to test your code by hand line by line and talk about Big(O).\n\n**Question 2:** https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree/\nI was very close to finish but there was not enough time left. I did bfs traversal on a tree and hash map to store each node.\n You should take 20-30 minutes to finish implementing efficient solution to the problem.  \n\nThen after 3 days, I got rejected after I contacted my recruiter about the result. My advice to anyone interviewing with Facebook:\na) you either get 1 easy and 1 medium level question. In such cases, you should finish coding easy level question in max 15 mins and medium level in 20-30 mins.\nb) or they might ask you 1 Hard question which you should solve in 35-45 mins. \nc) or you might get 2 medium problems. 20-25 mins each.\n\nBest of luck

Question 1: https://leetcode.com/problems/valid-palindrome-ii/\nGiven a non-empty string s, you may delete at most one character. Judge whether you can make it 