Array Questions at Zomato: What to Expect

Array questions dominate Zomato's technical interviews, comprising 20 out of 29 total problems. This focus isn't arbitrary. Arrays are the fundamental data structure for representing real-world data at scale: restaurant listings, menu items, user locations, delivery routes, and time-series data like order histories. Mastering array manipulation is essential because it tests a candidate's ability to handle contiguous data blocks efficiently—a daily requirement for building and optimizing Zomato's high-throughput platforms.

What to Expect — Types of Problems

Zomato's array problems test core algorithmic patterns applied to practical scenarios. Expect heavy emphasis on:

• Two Pointers & Sliding Window: Crucial for optimizing operations on sorted data (like finding restaurant pairs within a delivery radius) or analyzing contiguous sequences (e.g., maximum orders in a time window).
• Sorting & Searching: Frequently used for organizing and retrieving data, such as ranking search results or finding the nearest delivery partner.
• Prefix Sum & Hashing: Essential for fast range queries (e.g., total orders in a region over a period) and duplicate detection (like identifying duplicate menu entries).
• In-place Array Manipulation: Tests your ability to modify data efficiently without extra space, mirroring memory-conscious backend operations.

The problems often layer these patterns, requiring you to combine techniques to find an optimal solution.

How to Prepare — Study Tips with One Code Example

Focus on understanding patterns, not memorizing solutions. For each problem type, learn the underlying logic and practice variations. Time and space complexity analysis is non-negotiable.

A key pattern is the Two-Pointer technique for a sorted array. Consider finding two numbers in a sorted list that sum to a target (analogous to finding two restaurants whose combined rating meets a threshold).

def two_sum_sorted(numbers, target):
    left, right = 0, len(numbers) - 1
    while left < right:
        current_sum = numbers[left] + numbers[right]
        if current_sum == target:
            return [left, right]
        elif current_sum < target:
            left += 1
        else:
            right -= 1
    return [-1, -1]

Recommended Practice Order

Build competence progressively:

1. Start with fundamental in-place operations (rotations, removals).
2. Master sorting, searching, and basic two-pointer problems.
3. Advance to sliding window and prefix sum applications.
4. Tackle problems combining multiple patterns (e.g., hashing with prefix sum).
5. Finally, solve Zomato's specific array problems under timed conditions.

This structured approach ensures you develop the pattern recognition and efficient coding skills needed to succeed.

Practice Array at Zomato