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4 Rounds ~21 Days Hard
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The Interview Loop

Recruiter Screen (30 min)

Standard fit check, behavioral questions, and resume overview.

Technical Loop (3-4 Rounds)

Deep dive into domain knowledge, coding, and system design.

Interview Question Bank

Software Engineer • Coding • medium

Given the root of a binary tree, collect a tree's nodes as if you were doing this: Collect all the leaf nodes. Remove all the leaf nodes. Repeat until the tree is empty.

#Tree #Depth-First Search #Binary Tree
Practice
Software Engineer • Coding • medium

Design a class which receives a list of words in the constructor, and implements a method that takes two words word1 and word2 and return the shortest distance between these two words in the list. The method will be called repeatedly.

#Array #Hash Table #Two Pointers #Design
Practice
Software Engineer • Coding • medium

Given a nested list of integers, return the sum of all integers in the list weighted by their depth. Each element is either an integer, or a list -- whose elements may also be integers or other lists. The depth is defined such that leaves have a weight of 1, and the root has the maximum weight.

#Depth-First Search #Breadth-First Search
Practice
Software Engineer • Coding • easy

Given two strings s and t, determine if they are isomorphic. Two strings s and t are isomorphic if the characters in s can be replaced to get t.

#Hash Table #String
Practice
Software Engineer • Coding • hard

Design an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary tree can be serialized to a string and this string can be deserialized to the original tree structure.

#Tree #Depth-First Search #Breadth-First Search #Design #String
Practice
Software Engineer • Coding • hard

Given a string s, return true if s is a valid number. For example, '2', '0089', '-0.1', '+3.14', '4.', '-.9', '2e10', '-90E3', '3e+7', '+6e-1', '53.5e93', '-123.456e789' are valid.

#String #Math
Practice
Software Engineer • Coding • hard

Given an array of strings words and a width maxWidth, format the text such that each line has exactly maxWidth characters and is fully (left and right) justified.

#Array #String #Simulation
Practice
Software Engineer • Coding • medium

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cover all the intervals in the input.

#Array #Sorting
Practice
Software Engineer • Coding • medium

Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.

#Tree #Depth-First Search #Binary Tree
Practice
Software Engineer • Coding • easy

You have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted in adjacent plots. Given an integer array flowerbed containing 0's and 1's, and an integer n, return true if n new flowers can be planted.

#Array #Greedy
Practice
Software Engineer • Coding • medium

There is an integer array nums sorted in ascending order (with distinct values). Prior to being passed to your function, nums is possibly rotated at an unknown pivot index. Given the array nums after the possible rotation and an integer target, return the index of target if it is in nums, or -1 if it is not in nums.

#Array #Binary Search
Practice
Software Engineer • Coding • easy

Given an integer array nums, find the subarray with the largest sum, and return its sum.

#Array #Dynamic Programming #Divide and Conquer
Practice
Software Engineer • Coding • medium

Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. If target is not found in the array, return [-1, -1]. You must write an algorithm with O(log n) runtime complexity.

#Array #Binary Search
Practice
Software Engineer • Coding • medium

Implement the RandomizedSet class: insert(val), remove(val), and getRandom(). Each function must run in average O(1) time complexity.

#Array #Hash Table #Math #Design #Randomized
Practice
Software Engineer • Coding • hard

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. Given two words, beginWord and endWord, and a dictionary wordList, return the number of words in the shortest transformation sequence.

#Hash Table #String #Breadth-First Search
Practice
Software Engineer • Coding • hard

Given a graph representing LinkedIn connections, write a function to find the shortest path (degrees of separation) between two members.

#Graph #BFS #Shortest Path
Practice
Software Engineer • Coding • medium

Given a nested list of integers, return the sum of all integers in the list weighted by their depth. (Nested List Weight Sum)

#DFS #BFS #Array
Practice
Software Engineer • Coding • medium

Given a list of intervals representing a user's work experiences (start_year, end_year), merge all overlapping experiences to find the total years of experience.

#Array #Sorting #Intervals
Practice
Software Engineer • Coding • medium

Given an integer array nums, return the number of triplets chosen from the array that can make triangles if we take them as side lengths of a triangle.

#Array #Two Pointers #Sorting #Greedy
Practice
Software Engineer • Coding • easy

Design a data structure that supports the following operations: add(number) and find(value). find(value) returns true if there exists any pair of numbers whose sum is equal to the value.

#Design #Hash Table #Two Pointers
Practice
Software Engineer • Coding • hard

Given a binary tree, design an algorithm to serialize and deserialize it.

#Tree #String #Design #DFS/BFS
Practice
Software Engineer • Coding • medium

Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value.

#Binary Search #Array
Practice
Software Engineer • Coding • medium

Given a string s, return all the palindromic permutations (without duplicates) of it. Return an empty list if no palindromic permutation could be form.

#Backtracking #Hash Table #String
Practice
Software Engineer • Coding • medium

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.

#Array #Dynamic Programming #Divide and Conquer
Practice
Software Engineer • Coding • medium

Evaluate the value of an arithmetic expression in Reverse Polish Notation.

#Stack #Math #Array
Practice
Software Engineer • Coding • medium

Given a nested list of integers, return the sum of all integers in the list weighted by their depth. However, the weight is defined from bottom up. (Nested List Weight Sum II)

#DFS #BFS #Math
Practice
Software Engineer • Coding • medium

Given the root of a binary tree, return the lowest common ancestor of two given nodes in the tree.

#Tree #DFS
Practice
Software Engineer • Coding • medium

There is an integer array nums sorted in ascending order (with distinct values) that is possibly rotated. Given the array nums after the possible rotation and an integer target, return the index of target if it is in nums, or -1 if it is not in nums.

#Binary Search #Array
Practice

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Senior Engineer

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