Meta Phone Screen Experience: K+1th Largest Element and Valid Palindrome
Summary
I had a Meta phone screen where I was asked to solve 'K+1th Largest Element' and 'Valid Palindrome'. Despite providing correct solutions and detailed explanations, the interview was frustrating due to vague feedback and ultimately resulted in a rejection.
Full Experience
I recently experienced a Meta phone screen where I was presented with two coding questions. Although I felt well-prepared, the interview left me quite frustrated due to the interviewer's feedback style.
For the first question, 'K+1th Largest Element', I quickly understood the min-heap approach, discussed its complexities, and implemented a solution. I initially made a slight mistake by removing elements before adding new ones but debugged it to ensure elements were added first, then removed if the heap size exceeded K+1. The interviewer probed an edge case with array size 2 and K=2, leading to K+1=3, which I correctly identified as an impossible scenario, suggesting an exception. I implemented this, but the interviewer repeatedly claimed my code had 'bugs' without identifying specific issues, even after I walked through it line by line. This vague feedback was confusing and unsupportive.
The second question was 'Valid Palindrome', requiring me to check if a string is a palindrome while ignoring non-alphanumeric characters and case. I was very familiar with this and quickly implemented a two-pointer solution. Initially, I converted the whole string to lowercase, but the interviewer pointed out the unnecessary space complexity. I adjusted to handle characters in-place, converting to lowercase only when needed. I also refined my code to reduce the number of if conditions. Despite my correct solution and thorough explanation, the interviewer's body language suggested dissatisfaction, which made me feel my efforts weren't being recognized.
Ultimately, I arrived at correct solutions for both problems and was confident in my explanations. However, the lack of clear, actionable feedback and the persistent, unspecific claims of 'bugs' made the experience frustrating. I later received a rejection email, which, though disappointing, is a part of the process. I am now moving on to new opportunities.
Interview Questions (2)
The first question was to find the K+1-th largest element using a min-heap. I was familiar with this problem and quickly explained the approach, discussed complexities, and implemented a solution. Initially, I made a mistake in the order of operations by removing elements from the heap before adding new ones. After debugging line by line, I fixed the issue by ensuring elements were added first and removed only if the heap size exceeded K+1.
The interviewer then asked about an edge case where the array size was 2 and K = 2, making K+1 = 3. I explained that finding the 3rd largest element in an array of size 2 is impossible and suggested throwing an exception. The interviewer agreed with this, so I implemented it. However, they repeatedly insisted there were still "bugs" in my code. Despite running through the code properly and confirming the correct output for all test cases, they claimed I was skipping steps. To address this, I walked through the code line by line with comments, but the interviewer still thought the solution was buggy without identifying specific issues. This left me feeling confused and unsupported.
The second question required checking if a string is a valid palindrome, ignoring digits and any non-letter characters, and considering case insensitivity. I was well-prepared for this question and quickly implemented a two-pointer solution. Initially, I converted the string to lowercase at the start, but the interviewer pointed out that this increased space complexity unnecessarily. I adjusted my code to handle characters in-place by converting them to lowercase only when needed.
The interviewer also suggested reducing the number of if conditions. I addressed this feedback by combining checks into a single condition within the loop. While my solution was correct, and I explained my thought process thoroughly, the interviewer’s body language suggested dissatisfaction, making me feel like my efforts weren’t being fully recognized.
Preparation Tips
I felt well-prepared for the interview, especially for standard data structure and algorithm problems, which allowed me to quickly approach and solve the given questions.