Array Questions at Agoda: What to Expect

Array questions dominate Agoda's technical interviews, making up 30 of their 46 most frequently asked problems. This isn't a coincidence. Agoda's core business—handling hotel bookings, search results, pricing data, and user sessions—relies heavily on efficient data processing. Arrays are the fundamental structure for storing and manipulating these ordered lists of information, such as sorted hotel prices, date ranges for availability, or sequences of user actions. Mastering array manipulation is not just about solving an interview problem; it's demonstrating you can think about the real-world, scalable data processing that powers a global travel platform. If you're interviewing at Agoda, your performance on array problems will be a significant predictor of your success.

What to Expect — Types of Problems

Agoda's array questions tend to focus on practical application and algorithmic efficiency. You can expect the following categories:

1. Two Pointers & Sliding Window: This is the most critical pattern for Agoda. It's used for problems involving subarrays, sorted data, or minimizing/maximizing a condition within a window. Think finding pairs with a target sum in sorted price lists, or the longest subarray with a certain property.
2. Prefix Sum & Hashing: Frequently tested for problems related to subarray sums, especially finding if a contiguous subarray sums to a target value (like a specific transaction total). This often involves using a hash map to store prefix sums for O(1) lookups.
3. In-place Array Manipulation: Questions that ask you to modify the given array without using extra space, such as moving zeros, removing duplicates from a sorted array, or applying a rotation. This tests your understanding of memory constraints.
4. Simulation & Index Mapping: Some problems require carefully traversing the array according to specific rules or using the array indices themselves as a data structure (like the "first missing positive" problem).

The problems often have a "data stream" or "sequence" flavor, reflecting real-time travel data processing.

How to Prepare — Study Tips with One Code Example

Your preparation should be pattern-focused, not just problem-focused. Learn to recognize the underlying technique.

1. Master the Two Pointers/Sliding Window pattern first. It's Agoda's favorite.
2. Practice drawing it out. Before coding, sketch the array, pointers, and window. Track variables on paper.
3. Time and space complexity is non-negotiable. Always state it and be prepared to justify why your solution is optimal.
4. Write clean, production-ready code. Use meaningful variable names, add brief comments for logic, and handle edge cases (empty array, single element, large inputs).

Let's look at a classic Sliding Window example: finding the length of the longest subarray with a sum less than or equal to a target k.

def longest_subarray_sum_k(nums, k):
    max_length = 0
    window_sum = 0
    left = 0

    for right in range(len(nums)):
        window_sum += nums[right]
        # Shrink the window from the left while sum > k
        while window_sum > k and left <= right:
            window_sum -= nums[left]
            left += 1
        # Update max_length if current window is valid
        max_length = max(max_length, right - left + 1)
    return max_length

Recommended Practice Order

Tackle the 30 Agoda array questions in this strategic order to build competence efficiently:

1. Foundation: Start with basic in-place operations (Remove Duplicates, Move Zeroes) and simple two-pointer problems (Two Sum on a sorted array).
2. Core Patterns: Dive deep into Sliding Window (both fixed and variable size) and Prefix Sum problems. This is the bulk of your work.
3. Combination & Optimization: Practice problems that combine techniques, like using a hash map with two pointers, or that require non-trivial index manipulation.
4. Agoda-Specific List: Finally, run through all 30 Agoda-tagged problems on CodeJeet in a timed setting to simulate the interview environment.

Practice Array at Agoda