JioStar Android App Developer Interview Questions and Answers

Round duration - 60 minutes
Round difficulty - Easy

Technical interview round. I was asked 2 DSA problems to discuss and code.

Q1. 
Binary Array Sorting Problem Statement
You are provided with a binary array, i.e., an array containing only 0s and 1s. Your task is to sort this binary array and return it after sorting.
Input:
 The fir...read more
Ans. 
Yes, the binary array sorting problem can be solved in linear time and constant space by using a two-pointer approach.
• Use two pointers, one starting from the beginning of the array and the other starting from the end.

• Swap 0s to the left side and 1s to the right side by incrementing and decrementing the pointers accordingly.

• Continue this process until the two pointers meet in the middle of the array.

• Example: Input: [1,
Answered by AI
Add your answer
Q2. 
Maximum Subarray Sum Problem Statement
Given an array arr of length N consisting of integers, find the sum of the subarray (including empty subarray) with the maximum sum among all subarrays.
Explanation...read more
Ans. 
Find the sum of the subarray with the maximum sum among all subarrays in a given array.
• Iterate through the array and keep track of the maximum sum subarray encountered so far.

• Use Kadane's algorithm to efficiently find the maximum subarray sum.

• Consider the case where all elements in the array are negative.

• Handle the case where the array contains only one element.
Answered by AI
Add your answer

Round duration - 60 minutes
Round difficulty - Medium

Technical interview round. I was asked questions related to Android and its architecture.

Q1. How does RecyclerView work internally?
Ans. 
RecyclerView is a flexible view for providing a limited window into a large data set.
• RecyclerView recycles views to improve performance and memory usage.

• It uses a LayoutManager to organize and position items within the view.

• Adapter provides data to be displayed in the RecyclerView.

• ItemDecoration allows for custom drawing of item decorations like borders or dividers.
Answered by AI
View 2 more answers
Q2. Can you explain how to implement a ViewModel in Android?
Ans. 
ViewModel in Android is a class that is responsible for preparing and managing data for an activity or fragment.
• ViewModel is part of the Android Architecture Components and is used to store and manage UI-related data in a lifecycle-conscious way.

• It survives configuration changes such as screen rotations and retains data during the lifecycle of the activity or fragment.

• ViewModel should never hold a reference to a view o...read more
Answered by AI
Add your answer