eBay Interview Questions

Determine if a given array of numbers can be divided into two subsets with equal sums. Essentially, can you split the array so both sides add up to the same value?

Determine if removing a single element from an array can make the remaining elements strictly increasing. You need to check if it's possible to obtain a strictly increasing sequence by deleting at most one element.

Design a data structure that acts as a Least Recently Used (LRU) cache. Implement methods to get and put key-value pairs, evicting the least recently used entry when the cache is full.

Determine if one binary tree is a subtree of another binary tree. That is, check if the structure and node values of the smaller tree exactly match a portion of the larger tree.

Calculate the alternating sum of digits in a given number. You'll add the first digit, subtract the second, add the third, and so on.

Implement a Skiplist data structure that supports efficient search, insertion, and deletion of elements. A Skiplist is a probabilistic data structure with multiple levels of linked lists.

You're given an array of numbers. Pair them up to minimize the largest sum among all pairs.

Find the longest sequence of consecutive zeros (the binary gap) between ones in the binary representation of a given positive integer.

Find the shortest subsequence in a string S that contains all characters of another string T in the correct order. You need to find the minimum window in S that is a subsequence of T.

Given a grid representing land and water, count the number of distinct islands. An island is formed by connected land cells.

Traverse a given matrix in a spiral pattern, returning all elements in the order you visit them. Essentially, walk around the matrix layer by layer, adding elements to a list.

Transform one word into another, one letter at a time, using only words from a given dictionary. Find the shortest sequence of words to reach the target.

You're given a lock with four dials, each 0-9. Find the minimum number of turns to open the lock to a target combination, avoiding a list of dead ends.

Determine if it is possible to finish all courses given prerequisites. Some courses must be taken before others; can you find a valid order?

You are given a board of characters and a list of words. Find all the words from the list that can be formed by traversing adjacent cells on the board.

Given an array, rearrange it so that all zeros are moved to the end while maintaining the relative order of the non-zero elements.

Traverse a binary tree level by level. Return the nodes in a list, alternating the order of nodes from left to right and right to left for each level.

Given a matrix, if any element is zero, set its entire row and column to zero. Do this in-place.

You're given a list of courses and their prerequisites. Determine a valid order in which you can take all the courses, respecting the dependencies. If it's impossible to finish all courses, indicate that.

Determine if a string containing parentheses is valid. A valid string has matching and properly nested opening and closing parentheses.