Find the first character in a stream which is not repeated in the rest of the stream. Please note that you are being provided a stream as a source for these characters. The stream is guaranteed to eventually terminate (i.e. return false from a call to the hasNext() method), though it could be very long. You will access this stream through the provided interface methods. A call to hasNext() will return whether the stream contains any more characters to process. A call to getNext() will return the next character to be processed in the stream. It is not possible to restart the stream.
Example:
Input: aAbBABac
Output: b
In this example, the character ‘b’ is the first character in the stream which is not repeated in the stream.
Interviewed for silicon team. Have only been asked about the domain specific knowledge in 1st round and system design in 2nd round and C coding in 3rd round.
The interviews were 50 mins each.
The phone screen went longer than expected, focusing heavily on implementation details. The interviewer really grilled me on my approach to a Least Recently Used (LRU) cache, asking how I'd combine a hashmap with a doubly linked list. I felt well-prepared since I had gone through system design examples on PracHub, which made me comfortable discussing eviction policies. The later rounds included more technical questions and behavioral interviews, but in the end, I received an offer, though I ultimately decided to decline. Overall, I’d say the process was average, with solid questions.
Interview questions [1]
Question 1
Design and implement a Least Recently Used (LRU) cache supporting get(key) and put(key, value) in O(1) average time. Walk through combining a hashmap with a doubly linked list, eviction policy when capacity is exceeded, and how you'd extend it to handle thread-safe concurrent access.
Recruiter reaches out after applying through Amazon careers, no referral. Had an initial OA, then after a month had four rounds in two days - three coding one system design. Each round had 30 min behavioral and 30 min coding.
Interview questions [1]
Question 1
Questions were mainly hashmap, sliding window and interval related.