Nvidia Coding Interview Questions

Last Stone Weight

You are given an array of integers stones where stones[i] is the weight of the ith stone.

LRU Cache

Design a data structure that follows the constraints of a Least Recently Used (LRU) cache.

Group Anagrams

Given an array of strings strs, group the anagrams together. You can return the answer in any order.

Minimum Operations to Reduce an Integer to 0

You are given a positive integer n, you can do the following operation any number of times:

Special Binary String

Special binary strings are binary strings with the following two properties:

Best Time to Buy and Sell Stock

You are given an array prices where prices[i] is the price of a given stock on the ith day.

Two Sum

Given an array of integers nums and an integer target, return the indices of the two numbers that add up to target.

Longest Substring Without Repeating Characters

Given a string s, find the length of the longest substring without duplicate characters.

Number of Islands

Given an m x n 2D binary grid grid which represents a map of '1's (land) and '0's (water), return the number of islands.

Maximum Subarray

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

Add Two Numbers

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a sing...

Search in Rotated Sorted Array

There is an integer array nums sorted in ascending order (with distinct values).

Maximum Number of Visible Points

You are given an array points, an integer angle, and your location, where location = [posx, posy] and points[i] = [xi, yi] both denote integral coordinates on t...

Reverse Bits

Reverse bits of a given 32 bits signed integer.

Missing Number

Given an array nums containing n distinct numbers in the range [0, n], return the only number in the range that is missing from the array.

Valid Parentheses

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

Merge Intervals

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

Task Scheduler II

You are given a 0-indexed array of positive integers tasks, representing tasks that need to be completed in order, where tasks[i] represents the type of the ith...

Merge k Sorted Lists

You are given an array of k linked-lists lists, each linked-list is sorted in ascending order.

Move Zeroes

Given an integer array nums, move all 0's to the end of it while maintaining the relative order of the non-zero elements.

Rotate Image

You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).

Find Median from Data Stream

The median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value, and the median is the mean of the two midd...

Copy List with Random Pointer

A linked list of length n is given such that each node contains an additional random pointer, which could point to any node in the list, or null.

Fibonacci Number

The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, startin...

String to Integer (atoi)

Implement the myAtoi(string s) function, which converts a string to a 32-bit signed integer.

Climbing Stairs

You are climbing a staircase. It takes n steps to reach the top.

Kth Largest Element in an Array

Given an integer array nums and an integer k, return the kth largest element in the array.

Break a Palindrome

Given a palindromic string of lowercase English letters palindrome, replace exactly one character with any lowercase English letter so that the resulting string...

Insert Delete GetRandom O(1)

Implement the RandomizedSet class:

Rectangle Area

Given the coordinates of two rectilinear rectangles in a 2D plane, return the total area covered by the two rectangles.

Trapping Rain Water

Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining.

Find the Duplicate Number

Given an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.

Generate Parentheses

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

H-Index

Given an array of integers citations where citations[i] is the number of citations a researcher received for their ith paper, return the researcher's h-index.

Maximal Square

Given an m x n binary matrix filled with 0's and 1's, find the largest square containing only 1's and return its area.

Single Element in a Sorted Array

You are given a sorted array consisting of only integers where every element appears exactly twice, except for one element which appears exactly once.

Binary Tree Maximum Path Sum

A path in a binary tree is a sequence of nodes where each pair of adjacent nodes in the sequence has an edge connecting them. A node can only appear in the sequ...

Spiral Matrix

Given an m x n matrix, return all elements of the matrix in spiral order.

Intersection of Two Linked Lists

Given the heads of two singly linked-lists headA and headB, return the node at which the two lists intersect. If the two linked lists have no intersection at al...

Reverse Linked List II

Given the head of a singly linked list and two integers left and right where left <= right, reverse the nodes of the list from position left to position right,...

Validate Binary Search Tree

Given the root of a binary tree, determine if it is a valid binary search tree (BST).

Snapshot Array

Implement a SnapshotArray that supports the following interface:

Sliding Puzzle

On an 2 x 3 board, there are five tiles labeled from 1 to 5, and an empty square represented by 0. A move consists of choosing 0 and a 4-directionally adjacent...

Delete Duplicate Folders in System

Due to a bug, there are many duplicate folders in a file system. You are given a 2D array paths, where paths[i] is an array representing an absolute path to the...

Reverse Integer

Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1...

Merge Sorted Array

You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and num...

Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings.

Majority Element

Given an array nums of size n, return the majority element.

Find Peak Element

A peak element is an element that is strictly greater than its neighbors.

House Robber

You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from rob...

Reverse Linked List

Given the head of a singly linked list, reverse the list, and return the reversed list.

Set Matrix Zeroes

Given an m x n integer matrix matrix, if an element is 0, set its entire row and column to 0's.

Find Pivot Index

Given an array of integers nums, calculate the pivot index of this array.

Course Schedule II

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, b...

Best Time to Buy and Sell Stock IV

You are given an integer array prices where prices[i] is the price of a given stock on the ith day, and an integer k.

Design HashMap

Design a HashMap without using any built-in hash table libraries.

Implement Trie (Prefix Tree)

A trie (pronounced as "try") or prefix tree is a tree data structure used to efficiently store and retrieve keys in a dataset of strings. There are various appl...

Minimum Size Subarray Sum

Given an array of positive integers nums and a positive integer target, return the minimal length of a subarray whose sum is greater than or equal to target. If...

Intersection of Two Arrays

Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must be unique and you may return the result in any...

Max Points on a Line

Given an array of points where points[i] = [xi, yi] represents a point on the X-Y plane, return the maximum number of points that lie on the same straight line.

Serialize and Deserialize Binary Tree

Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitte...

Ways to Make a Fair Array

You are given an integer array nums. You can choose exactly one index (0-indexed) and remove the element. Notice that the index of the elements may change after...

Keys and Rooms

There are n rooms labeled from 0 to n - 1 and all the rooms are locked except for room 0. Your goal is to visit all the rooms. However, you cannot enter a locke...

Maximum Sum of Distinct Subarrays With Length K

You are given an integer array nums and an integer k. Find the maximum subarray sum of all the subarrays of nums that meet the following conditions:

Find The Original Array of Prefix Xor

You are given an integer array pref of size n. Find and return the array arr of size n that satisfies:

Shuffle an Array

Given an integer array nums, design an algorithm to randomly shuffle the array. All permutations of the array should be equally likely as a result of the shuffl...

Double a Number Represented as a Linked List

You are given the head of a non-empty linked list representing a non-negative integer without leading zeroes.

Minimum Add to Make Parentheses Valid

A parentheses string is valid if and only if:

Counting Bits

Given an integer n, return an array ans of length n + 1 such that for each i (0 <= i <= n), ans[i] is the number of 1's in the binary representation of i.

Linked List Random Node

Given a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen.

Number of Operations to Make Network Connected

There are n computers numbered from 0 to n - 1 connected by ethernet cables connections forming a network where connections[i] = [ai, bi] represents a connectio...

Greatest Common Divisor of Strings

For two strings s and t, we say "t divides s" if and only if s = t + t + t + ... + t + t (i.e., t is concatenated with itself one or more times).

Subarray Product Less Than K

Given an array of integers nums and an integer k, return the number of contiguous subarrays where the product of all the elements in the subarray is strictly le...

Remove Nth Node From End of List

Given the head of a linked list, remove the nth node from the end of the list and return its head.

Rectangle Overlap

An axis-aligned rectangle is represented as a list [x1, y1, x2, y2], where (x1, y1) is the coordinate of its bottom-left corner, and (x2, y2) is the coordinate...

Valid Sudoku

Determine if a 9 x 9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:

Is Subsequence

Given two strings s and t, return true if s is a subsequence of t, or false otherwise.

Sort Characters By Frequency

Given a string s, sort it in decreasing order based on the frequency of the characters. The frequency of a character is the number of times it appears in the st...

Remove Duplicates from Sorted List

Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well.

Maximum Product Subarray

Given an integer array nums, find a subarray that has the largest product, and return the product.

Range Sum Query 2D - Immutable

Given a 2D matrix matrix, handle multiple queries of the following type:

Swapping Nodes in a Linked List

You are given the head of a linked list, and an integer k.

Print in Order

Suppose we have a class:

Course Schedule

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, b...

Coin Change

You are given an integer array coins representing coins of different denominations and an integer amount representing a total amount of money.

Single Number

Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.

Fizz Buzz

Given an integer n, return a string array answer (1-indexed) where:

Robot Bounded In Circle

On an infinite plane, a robot initially stands at (0, 0) and faces north. Note that:

Delete Node in a Linked List

There is a singly-linked list head and we want to delete a node node in it.

3Sum

Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0.

Validate IP Address

Given a string queryIP, return "IPv4" if IP is a valid IPv4 address, "IPv6" if IP is a valid IPv6 address or "Neither" if IP is not a correct IP of any type.

Min Stack

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.

All Possible Full Binary Trees

Given an integer n, return a list of all possible full binary trees with n nodes. Each node of each tree in the answer must have Node.val == 0.

Longest Increasing Path in a Matrix

Given an m x n integers matrix, return the length of the longest increasing path in matrix.