Ripplr Front end Developer Interview Questions and Answers

Round duration - 180 Minutes
Round difficulty - Medium

It had some coding questions related to graph.

Q1. 
Dijkstra's Shortest Path Problem Statement
You are given an undirected graph with V vertices (numbered from 0 to V-1) and E edges. Each edge connects two nodes u and v and has an associated weight represe...read more
Ans. 
The question is about finding the shortest path distance from a source node to all vertices in an undirected graph.
• The graph is represented by the number of vertices and edges, followed by the edges and their distances.

• The task is to find the shortest path distance from the source node (0) to all other nodes.

• If a node is disconnected from the source node, print the maximum positive integer value (2147483647).

• Implement ...read more
Answered by AI
Add your answer
Q2. 
Path Existence in Directed Graph
Given a directed and unweighted graph characterized by vertices 'V' and edges 'E', determine if a path exists from a specified 'source' vertex to a 'destination' vertex. T...read more
Ans. 
The task is to check if there exists a path from a given source vertex to a destination vertex in a directed and unweighted graph.
• Read the number of test cases.

• For each test case, read the number of vertices and edges.

• Read the edges of the graph.

• Read the source and destination vertices.

• Implement a graph traversal algorithm (e.g., BFS or DFS) to check if a path exists from the source to the destination.

• Print 'true' if a...read more
Answered by AI
Add your answer

Round duration - 180 Minutes
Round difficulty - Hard

The round was really tough only 1 coding question was asked

Q1. 
Encode N-ary Tree to Binary Tree Problem Statement
You are provided with an N-ary tree constituted of 'N' nodes, where node '1' is the head of the tree. Your task is to encode this N-ary tree into a binar...read more
Ans. 
The task is to encode an N-ary tree into a binary tree and then decode the binary tree back into the original N-ary tree.
• Encode the N-ary tree by representing each node as a binary tree node with its first child as the left child and subsequent children as the right child.

• To decode the binary tree, traverse the binary tree and for each node, create a new N-ary tree node with its left child as the first child and subseq...read more
Answered by AI
Add your answer

Q1. Question on tree
Add your answer
Q2. Question on sql in deep
Add your answer

Q1. Explain hoisting in js
Ans. 
Hoisting in JavaScript is the behavior where variable and function declarations are moved to the top of their containing scope during the compilation phase.
• Variable declarations are hoisted to the top of their scope, but not their assignments.

• Function declarations are fully hoisted, meaning they can be called before they are declared.

• Hoisting can lead to unexpected behavior if not understood properly.
Answered by AI
Add your answer
Q2. Explain closures in js
Ans. 
Closures in JavaScript allow functions to access variables from their outer scope even after the outer function has finished executing.
• Closures are created when a function is defined within another function and the inner function has access to the outer function's variables.

• Closures can be used to create private variables and functions in JavaScript.

• Closures can also be used to maintain state in asynchronous operations...read more
Answered by AI
Add your answer

Q1. Javascript polyfills
Add your answer

Round duration - 60 Minutes
Round difficulty - Easy

Formal Introduction.
Asked About Projects.
Difference between SQL and NoSQL. Pros and Cons. Where should we use SQL and NoSQL.
Given a problem, I have to make a SQL Database structure and then interviewer told me to convert it into NoSQL.
asked coding questions

Q1. 
Search In Rotated Sorted Array Problem Statement
Given a sorted array of distinct integers that has been rotated clockwise by an unknown amount, you need to search for a specified integer in the array. Fo...read more
Ans. 
Implement a search function to find a specified integer in a rotated sorted array.
• Implement a binary search algorithm to find the target integer in the rotated sorted array.

• Handle the cases where the target integer may lie in the left or right half of the rotation.

• Keep track of the mid element and adjust the search range based on the rotation.

• Return the index of the target integer if found, else return -1.
Answered by AI
Add your answer
Q2. 
Zigzag Binary Tree Traversal Problem
Given a binary tree, compute the zigzag level order traversal of the node values in the tree. The zigzag traversal requires traversing levels from left to right, then ...read more
Ans. 
Zigzag level order traversal of a binary tree is computed by alternating between left to right and right to left traversal at each level.
• Use a queue to perform level order traversal of the binary tree.

• Maintain a flag to switch between left to right and right to left traversal at each level.

• Store the node values in a list while traversing and alternate the order based on the flag.

• Example: For input 1 2 3 4 -1 5 6 -1 7 -...read more
Answered by AI
Add your answer

Computer Fundamentals

Q1. Flatten a binary tree
Ans. 
Flatten a binary tree by converting it into a linked list in-place.
• Use a recursive approach to flatten the binary tree.

• Traverse the tree in a pre-order manner and keep track of the previous node.

• Set the left child of each node to null and the right child to the next node in the linked list.

• Example: Input: 1 -> 2 -> 5 -> 3 -> 4 -> null, Output: 1 -> null -> 2 -> null -> 3 -> null -> 4 -> null -> 5 -> null
Answered by AI
Add your answer

Round duration - 90 minutes
Round difficulty - Hard

Timing was late evening . Platform was good.

Q1. 
Largest Cycle in Maze Problem Statement
Given a maze represented by 'N' cells numbered from 0 to N-1, and an array arr of 'N' integers where arr[i] denotes the cell number that can be reached from the 'i'...read more
Ans. 
Identify the length of the largest cycle in a maze represented by cells and an array of integers.
• Iterate through each cell and find the cycle length using DFS or Floyd's Tortoise and Hare algorithm.

• Keep track of visited cells to avoid infinite loops.

• Return the length of the largest cycle found or -1 if no cycles exist.
Answered by AI
Add your answer

Round duration - 90 minutes
Round difficulty - Medium

The coding round was 90 minutes with 2 question and the difficulty was mid-range and both were graph question

Q1. 
Rat in a Maze Problem Statement
You need to determine all possible paths for a rat starting at position (0, 0) in a square maze to reach its destination at (N-1, N-1). The maze is represented as an N*N ma...read more
Ans. 
Find all possible paths for a rat in a maze from start to destination.
• Use backtracking to explore all possible paths in the maze.

• Keep track of visited cells to avoid revisiting them.

• Explore all possible directions (up, down, left, right) from each cell.

• Add the current direction to the path and recursively explore further.

• When reaching the destination, add the path to the list of valid paths.
Answered by AI
Add your answer

3 Graph Questions Were asked of difficulty medium to hard.

Hackathon round which revolved around multithreading