Meta SDE Interview Questions and Answers

Find an index in array where sum of elements on left side is equal to sum of elements on right side.

• Loop through array and calculate sum of all elements

• Then loop through array again and check if sum of elements on left side is equal to sum of elements on right side

• Return the index if found, else return -1

Find minimum number of jumps required to reach end of array with max moves in right direction at each index.

• Use dynamic programming approach to solve the problem

• Maintain an array to store minimum number of jumps required to reach each index

• Traverse the array and update the minimum number of jumps for each index

• Return the minimum number of jumps required to reach the end of array

Tournament tree is a binary tree where each node represents a match between two players/teams.

• Tournament tree is used in sports tournaments to determine the winner.

• The leaf nodes represent the players/teams and the internal nodes represent the matches.

• The winner of each match is the node with the higher score.

• Code can be written using a recursive function to traverse the tree and determine the winner.

Find 2 maximum elements in array in O(n+log(n)) comparison

• Use divide and conquer approach

• Divide array into two halves

• Recursively find max elements in each half

• Compare the two max elements to find the overall max elements

Find row with maximum 1s in a sorted 2D array of 0s and 1s.

• Use binary search to find the first occurrence of 1 in each row.

• Calculate the number of 1s in each row using the index found in step 1.

• Keep track of the row with maximum number of 1s.

• Time complexity: O(m log n), where m is the number of rows and n is the number of columns.

Efficiently check if a number is present in an array where each element differs by 1.

• Use binary search to find the element in the array

• Calculate the difference between the middle element and the first element

• If the difference is equal to the index of the middle element minus the index of the first element, then the left half of the array is consecutive

• If the difference is not equal, then the right half of the array is ...read more

Microsoft Excel

• Add more chart types (p1)

• Improve collaboration features (p2)

• Enhance data analysis tools (p3)

• Integrate with more external data sources (p4)

• Improve error handling and debugging (p5)

Program to rearrange shuffled 16 squares to get original big square

• Create a 4x4 matrix to represent the big square and fill it with shuffled squares

• Loop through the matrix and check if each square is in the correct position

• If a square is not in the correct position, swap it with the square in the correct position

• Repeat until all squares are in the correct position

The first declaration casts i to int pointer and dereferences it, while the second declaration casts the address of i to int pointer and dereferences it.

• The first declaration assumes i is already an int pointer.

• The second declaration takes the address of i and casts it to an int pointer.

• The first declaration may cause a segmentation fault if i is not an int pointer.

• The second declaration may cause unexpected behavior i...read more

Minimum comparisons needed to find median in unsorted array of size n

• For odd n, median is the middle element. For even n, median is the average of middle two elements

• Minimum comparisons needed for odd n is (n-1)/2. For even n, it is n/2

• Various sorting algorithms can be used to find median in an unsorted array

Time complexity to find an element in an alternatively sorted array.

• The time complexity will be O(log n) using binary search.

• Check the middle element and compare with the target element.

• If the middle element is greater than the target, search in the left half of the array.

• If the middle element is smaller than the target, search in the right half of the array.

• Repeat until the target element is found or the array is exha

Typing amazon.com in the browser's address bar takes you to Amazon's website.

• The browser sends a request to the DNS server to resolve the domain name 'amazon.com' to an IP address.

• The browser establishes a TCP connection with the server at the resolved IP address.

• The browser sends an HTTP request to the server for the homepage of Amazon's website.

• The server responds with the HTML code for the homepage, which the browse

The transaction process involves transferring funds from one account to another. A scheme is designed to ensure secure and accurate transfers.

• Verify the availability of sufficient funds in the sender's account

• Authenticate the sender's identity and authorization for the transaction

• Deduct the transfer amount from the sender's account balance

• Initiate a request to transfer the funds to the recipient's account

• Validate the r...read more

When a server receives an HTTP request, it interacts with the operating system, handles threading, thread pooling, synchronization, and hashing.

• Upon receiving an HTTP request, the server creates a new thread to handle the request.

• The operating system manages the allocation of system resources to the server process.

• Thread pooling is used to efficiently manage and reuse threads for handling multiple requests.

• Synchronizat...read more

ACID properties ensure reliability and consistency in database transactions.

• ACID stands for Atomicity, Consistency, Isolation, and Durability.

• Atomicity ensures that a transaction is treated as a single unit of work, either all or none of its operations are executed.

• Consistency ensures that a transaction brings the database from one valid state to another.

• Isolation ensures that concurrent transactions do not interfere w...read more

To find kth-smallest element in BST, perform inorder traversal and return the kth element.

• Perform inorder traversal of the BST

• Maintain a counter variable to keep track of the number of nodes visited

• When the counter reaches k, return the current node's value

• If k is greater than the number of nodes in the BST, return null or throw an exception

Find total possible valid unique combinations of given number of pairs of parenthesis without duplicity.

• Use recursion to generate all possible combinations

• Check for validity of each combination using a stack

• Use a set to avoid duplicity

Construct a binary tree from in-order traversal with nodes greater than left and right child.

• The root node will be the maximum value in the in-order traversal

• Recursively construct the left and right subtrees using the left and right portions of the in-order traversal

• Repeat until all nodes are added to the tree

An algorithm to find top 10 trending words inserted by users in sites like Twitter.

• Collect a large dataset of tweets

• Tokenize the tweets into individual words

• Remove stop words and punctuation

• Count the frequency of each word

• Sort the words by frequency in descending order

• Select the top 10 words

Find the first occurrence of 1 in a sorted binary array.

• Use binary search to find the first occurrence of 1.

• If the mid element is 1, check if it's the first occurrence or if the element before it is 0.

• If the mid element is 0, search in the right half of the array.

• If the mid element is 1 and the element before it is also 1, search in the left half of the array.

Remove duplicates from a string in O(n) without using hash

• Use an array of boolean values to keep track of characters already seen

• Iterate through the string and mark characters as seen in the array

• If a character has already been seen, remove it from the string

Find the first occurrence of 1 in a sorted infinite binary tree.

• Use binary search to traverse the tree.

• If the current node is 1, check if its left child is also 1. If yes, move to the left subtree, else return the current node.

• If the current node is 0, move to the right subtree.

• Repeat until the first occurrence of 1 is found or the tree is exhausted.

Find the second largest element in an array.

• Sort the array and return the second last element

• Iterate through the array and keep track of the two largest elements

• Use a priority queue to find the second largest element

Given a sorted array with repeated elements, find the occurrence of a given element using binary search.

• Use binary search to find the first occurrence of the element

• Use binary search to find the last occurrence of the element

• Calculate the occurrence by subtracting the indices of the last and first occurrences and adding 1

Implement a data structure and algorithm to print all files in a directory, including sub-directories.

• Use an n-ary tree or stack to represent the directory structure

• Implement a BFS or DFS algorithm to traverse the directory and print files

• Handle sub-directories recursively

• Consider using a queue or stack to keep track of directories to visit

Print a matrix diagonally.

• Start from the top left corner and print the diagonal elements

• Move down and right to print the next diagonal

• Repeat until all diagonals are printed

DFS is a traversal algorithm used to visit all nodes of a tree or graph. It can be applied to binary as well as n-ary trees.

• DFS stands for Depth First Search.

• In DFS, we start from the root node and visit its children recursively until we reach a leaf node.

• There are two types of DFS: Preorder (root, left, right) and Postorder (left, right, root).

• DFS can be implemented using recursion or a stack data structure.

• Example: I...read more

To find the top 10 selling products, sort the products by their sales count in descending order and select the first 10.

• Sort the products by their sales count in descending order

• Select the first 10 products from the sorted list

Design a valet parking lot with ticket assignment and car retrieval using best fit and nearest distance.

• Create a parking lot with designated spots for each size of car

• Assign a ticket to the customer upon entry and record the spot number

• Retrieve the car by searching for the nearest available spot of the appropriate size

• Use best fit algorithm to minimize empty spots

• Implement a system for payment upon exit