Role: Not Specified (Technical Interview)
College: Not Specified
Interview Date: Not Specified (Published Jul 23, 2025)
Interview Type: Not Specified
Result: Not Specified
Difficulty: Hard
Rounds: 3 Technical Rounds
Topics Asked: Data Structures (Doubly Linked List, Binary Tree, Skip Lists, LRU Cache), Algorithms, C/C++ Concepts, Synchronization, System Design
Experience:
This experience details three technical interview rounds covering a wide range of computer science fundamentals and problem-solving.
Round 1 (Technical Interview):
- Question 1: Given a sorted doubly linked list and two numbers C and K. Decrease the info of node with data K by C and insert the new node formed at its correct position such that the list remains sorted. Complete working code with test cases was required.
- Question 2: Given a binary tree, and two values a and b, find the shortest length between the nodes with info a and b.
- Question 3: Basics of synchronization, test and set, locks, mutex. The candidate wrote code and kept adding constraints, asking if the code would work in multiprocessor, uniprocessor, and multithreaded systems.
Round 2 (C/C++ concepts + HR): This round began with a detailed description of projects.
- Discussion on the details of the
printf function, format string, and variable arguments, and asked to implement a custom printf function.
- Interviewer wrote basic C programs on a shared screen, and output had to be predicted. Examples included:
int main(int argc , char *argv[]) { printf("%c",**++argv); }
int *x[N]; x=(int(*)[N])malloc(M*sizeof(*x)); printf("%d %d",sizeof(x),sizeof(*x));
- Asked the significance of the return statement in C and what '0' in
return(0) means.
- Questions based on pointing out errors in programs (e.g., modifying a read-only string, concepts of constant pointer to string).
- Question: 10000 students are there, and each student has one bit of data. How can you modify their data in O(1) time?
- Details on Structure Padding.
- Basic HR questions.
Round 3 (Technical Interview):
- Question 1: Given a large file which contains m rows and n columns. Given a column number, sort the column in such a way that corresponding rows are also sorted.
- Question 2: Suggest a way to search in a sorted linked list in better than O(n) time (Skip lists).
- Question 3: LRU cache implementation.
- Question 4: Find the mean and median of elements such that elements are dynamically added at runtime (approach only).
- Finally, "Why do you want to join Arista Networks?"