Hike Software Development Engineer Interview Questions and Answers for Experienced

Prints a linked list in a zigzag manner, alternating between left-to-right and right-to-left traversal.

• 1. Traverse the linked list level by level.

• 2. Use a flag to alternate the direction of printing for each level.

• 3. For odd levels, print from left to right; for even levels, print from right to left.

• 4. Example: For linked list 1 -> 2 -> 3 -> 4 -> 5, zigzag output would be: 1, 2, 3, 4, 5 (level 1), 5, 4, 3, ...read more

A photo viewer app for Android devices.

• Use RecyclerView to display a grid of photos

• Implement a caching mechanism to improve performance

• Support gestures for zooming and swiping between photos

• Integrate with a cloud storage service for photo storage and retrieval

• Implement a search feature to allow users to find specific photos

Check if any permutation of a string can form a palindrome by analyzing character frequencies.

• A palindrome reads the same forwards and backwards (e.g., 'racecar').

• For a string to have a permutation that is a palindrome, at most one character can have an odd frequency.

• Example: 'civic' can be rearranged to 'civic' (palindrome).

• Example: 'ivicc' can be rearranged to 'civic' (palindrome).

• Example: 'hello' cannot be rearrange...read more

Given an array of natural numbers, find the first missing natural number.

• Sort the array and iterate through it to find the first missing number.

• Use a hash set to keep track of the numbers present in the array.

• The first missing number will be the smallest positive integer not present in the array.

To transfer the Ball object from one thread to another in Android, we can use Handler or AsyncTask.

• Use Handler to post the Ball object from one thread to another

• Create a Handler in the receiving thread and use its post() method to receive the Ball object

• Alternatively, use AsyncTask to perform the transfer in the background thread and update the UI thread with the Ball object

IPC (Inter-Process Communication) methods in Android allow communication between different processes.

• Binder: Android's default IPC mechanism, provides high-performance communication between processes.

• AIDL (Android Interface Definition Language): Used to define the programming interface for IPC using Binder.

• Intents: Used for asynchronous communication between components within an application or between different applica...read more

Implement an LRU cache using a custom HashMap and a doubly linked list for efficient access and eviction.

• Use a HashMap to store key-value pairs for O(1) access.

• Maintain a doubly linked list to track the order of usage.

• On access, move the accessed node to the front of the list.

• On insertion, if the cache exceeds capacity, remove the least recently used node from both the list and the HashMap.

• Example: For a cache with cap...read more

A HashMap is a data structure that stores key-value pairs and provides constant time complexity for basic operations.

• Implement a hash function to convert keys into array indices

• Create an array to store the key-value pairs

• Handle collisions using a technique like chaining or open addressing

• Implement methods like put(), get(), and remove() to interact with the HashMap

Create a weather app that fetches and displays an image from a fixed URL upon button press.

• Use a button to trigger an API call to the fixed image URL.

• Handle the response to extract the image data.

• Display the image in a full-screen image view.

• Consider using libraries like Glide or Picasso for image loading.

• Ensure to handle errors, such as network issues or invalid responses.

To search for contacts with duplicate names and numbers, create a search function that checks both fields.

• Create a function that takes a search term as input

• Iterate through the list of contacts

• Check if the search term exists in the Name field or Num field

• Return the contacts that match the search term

Launch mode determines how a new instance of an activity is created and added to the task stack.

• Standard: Creates a new instance of the activity each time it is launched.

• SingleTop: If an instance of the activity already exists at the top of the stack, it will be reused.

• SingleTask: If an instance of the activity already exists in the stack, it will be brought to the front and cleared of any activities above it.

• SingleIns...read more

Deep linking in Android allows linking to specific content within an app, enabling seamless navigation.

• Deep linking is achieved by defining intent filters in the app's manifest file.

• The intent filter specifies the data format and scheme for the deep link.

• Deep links can be triggered from other apps, websites, or even notifications.

• Handling deep links involves extracting data from the intent and navigating to the appropr...read more

Design a screen to show 10 nearest restaurants in a list while keeping the UI uninterrupted.

• Use a scrollable list view to display the restaurants

• Implement a location-based search algorithm to find the nearest restaurants

• Include a search bar to allow users to search for specific restaurants

• Display relevant information for each restaurant such as name, rating, and distance

• Implement filters or sorting options to allow use...read more