Coding Interviews
Given a set of distinct integers, return the power set (all possible subsets including the empty set)
Given two binary strings a and b, return their sum as a binary string. ie "01" and "10" as strings add to "11"
You are given an array of non-overlapping intervals intervals where intervals[i] = [starti, endi] represent the start and the end of the ith interval and intervals is sorted in ascending order by starti. You are also given an interval newInterval = [start, end] that represents the start and end of another interval.
Insert newInterval into intervals such that intervals is still sorted in ascending order by starti and intervals still does not have any overlapping intervals (merge overlapping intervals if necessary).
Return intervals after the insertion.
Note that you don't need to modify intervals in-place. You can make a new array and return it.
Given an array of strings strs, group the anagrams together. You can return the answer in any order.
An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.
Given an integer array nums, you need to find one continuous subarray such that if you only sort this subarray in non-decreasing order, then the whole array will be sorted in non-decreasing order.
Return the shortest such subarray and output its length.
Given a string S and an integer K, return the length of the longest substring of S that contains at most K distinct characters.
Given a string s, find the length of the longest substring without repeating characters.
Design and implement a data structure for a LFU cache.
Implement the LFUCache class:
LFUCache(int capacity) Initializes the object with the capacity of the data structure.
int get(int key) Gets the value of the key if the key exists in the cache. Otherwise, returns -1.
void put(int key, int value) Update the value of the key if present, or inserts the key if not already present. When the cache reaches its capacity, it should invalidate and remove the least frequently used key before inserting a new item. For this problem, when there is a tie (i.e., two or more keys with the same frequency), the least recently used key would be invalidated.
To determine the least frequently used key, a use counter is maintained for each key in the cache. The key with the smallest use counter is the least frequently used key.
When a key is first inserted into the cache, its use counter is set to 1 (due to the put operation). The use counter for a key in the cache is incremented either a get or put operation is called on it.
The functions get and put must each run in O(1) average time complexity.
Given an integer array nums, return an integer array counts where counts[i] is the number of smaller elements to the right of nums[i].
Given an array nums of n integers where nums[i] is in the range [1, n], return an array of all the integers in the range [1, n] that do not appear in nums.
Given an integer array nums, rotate the array to the right by k steps, where k is non-negative.
Given two strings s and p, return an array of all the start indices of p's anagrams in s. You may return the answer in any order.
An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.
Design a social network website with the following functional requirements
1. Users should be able to post content with text, images or video 2. Users should be able to follow other users 3. Each user will have a relatively low latency feed which shows content posted by users they follow
Design a service with the following functional requirements
1. Users should be able to upload and download files
2. The files should be able to be shared with other users
3. Changes to the files should be pushed to other users with the content on their machine
4. There must be no risk of file corruption
5. Keep track of different versions of the files so they may be rolled back
6. Users should be able to edit files without an internet connection and the changes sync up when a connection becomes available
Functional Requirements
1. As users type text in a search box, show the top 10 auto complete results with very low latency
2. Analytics will be collected on what the user types
Design a url shortener service (similar to tinyurl).
1. Generate expiring unique short URL from provided URL
2. Redirect users to the correct website when they navigate to the short URL
A transformation sequence from word beginWord to word endWord using a dictionary wordList is a sequence of words beginWord -> s1 -> s2 -> ... -> sk such that:
Every adjacent pair of words differs by a single letter.
Every si for 1 <= i <= k is in wordList. Note that beginWord does not need to be in wordList.
sk == endWord
Given two words, beginWord and endWord, and a dictionary wordList, return all the shortest transformation sequences from beginWord to endWord, or an empty list if no such sequence exists. Each sequence should be returned as a list of the words [beginWord, s1, s2, ..., sk].
Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations in any order.
The same number may be chosen from candidates an unlimited number of times. Two combinations are unique if the frequency of at least one of the chosen numbers is different.
There are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array prerequisites where prerequisites[i] = [ai, bi] indicates that you must take course bi first if you want to take course ai.
For example, the pair [0, 1], indicates that to take course 0 you have to first take course 1.
Return true if you can finish all courses. Otherwise, return false.
Functional Requirements
The ability to set limits on the number of requests allowed within a specific timeframe
Keep performance and fault tolerance in mind