Visa Coding Interview Questions

Length Of Longest V Shaped Diagonal Segment

You are given a 2D integer matrix grid of size n x m, where each element is either 0, 1, or 2. A V-shaped diagonal segment starts with 1 and subsequent elements...

Two Sum

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

Split the Array

You are given an integer array nums of even length. You have to split the array into two parts nums1 and nums2 such that:

Rotating the Box

You are given an m x n matrix of characters boxGrid representing a side-view of a box. Each cell of the box is one of the following:

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.

Create Target Array in the Given Order

Given two arrays of integers nums and index. Your task is to create target array under the following rules:

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.

Maximum Number of Events That Can Be Attended

You are given an array of events where events[i] = [startDayi, endDayi]. Every event i starts at startDayi and ends at endDayi.

Longest Substring Without Repeating Characters

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

Divisor Game

Alice and Bob take turns playing a game, with Alice starting first.

Earliest Possible Day of Full Bloom

You have n flower seeds. Every seed must be planted first before it can begin to grow, then bloom. Planting a seed takes time and so does the growth of a seed....

Block Placement Queries

There exists an infinite number line, with its origin at 0 and extending towards the positive x-axis.

Odd String Difference

You are given an array of equal-length strings words. Assume that the length of each string is n.

Count Nodes With the Highest Score

There is a binary tree rooted at 0 consisting of n nodes. The nodes are labeled from 0 to n - 1. You are given a 0-indexed integer array parents representing th...

Group Anagrams

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

Two Furthest Houses With Different Colors

There are n houses evenly lined up on the street, and each house is beautifully painted. You are given a 0-indexed integer array colors of length n, where color...

Longest Common Prefix

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

LRU Cache

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

Valid Parentheses

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

Search in Rotated Sorted Array

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

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.

Text Justification

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) justifie...

Simplify Path

You are given an absolute path for a Unix-style file system, which always begins with a slash '/'. Your task is to transform this absolute path into its simplif...

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.

Number of Adjacent Elements With the Same Color

You are given an integer n representing an array colors of length n where all elements are set to 0's meaning uncolored. You are also given a 2D integer array q...

Minimum Operations to Write the Letter Y on a Grid

You are given a 0-indexed n x n grid where n is odd, and grid[r][c] is 0, 1, or 2.

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...

Longest Palindromic Substring

Given a string s, return the longest palindromic substring in s.

Reverse Words in a String

Given an input string s, reverse the order of the words.

Reverse Linked List

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

Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit

Given an array of integers nums and an integer limit, return the size of the longest non-empty subarray such that the absolute difference between any two elemen...

Maximum Subarray

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

Daily Temperatures

Given an array of integers temperatures represents the daily temperatures, return an array answer such that answer[i] is the number of days you have to wait aft...

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...

Diameter of Binary Tree

Given the root of a binary tree, return the length of the diameter of the tree.

Reverse Nodes in k-Group

Given the head of a linked list, reverse the nodes of the list k at a time, and return the modified list.

Find Peak Element

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

Word Search

Given an m x n grid of characters board and a string word, return true if word exists in the grid.

Restore IP Addresses

A valid IP address consists of exactly four integers separated by single dots. Each integer is between 0 and 255 (inclusive) and cannot have leading zeros.

Check If Array Pairs Are Divisible by k

Given an array of integers arr of even length n and an integer k.

Roman to Integer

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M.

Rotate String

Given two strings s and goal, return true if and only if s can become goal after some number of shifts on s.

Number of Black Blocks

You are given two integers m and n representing the dimensions of a 0-indexed m x n grid.

Word Ladder

A transformation sequence from word beginWord to word endWord using a dictionary wordList is a sequence of words beginWord -> s1 -> s2 -> ... -> sk such that:

Top K Frequent Elements

Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.

Shortest Palindrome

You are given a string s. You can convert s to a palindrome by adding characters in front of it.

Find Score of an Array After Marking All Elements

You are given an array nums consisting of positive integers.

Palindrome Number

Given an integer x, return true if x is a palindrome, and false otherwise.

Rotate Array

Given an integer array nums, rotate the array to the right by k steps, where k is non-negative.

Largest Number

Given a list of non-negative integers nums, arrange them such that they form the largest number and return it.

Valid Anagram

Given two strings s and t, return true if t is an anagram of s, and false otherwise.

Plus One

You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most sig...

Container With Most Water

You are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of the ith line are (i, 0) and (i, height[i]).

Valid Palindrome

A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the same forwa...

Edit Distance

Given two strings word1 and word2, return the minimum number of operations required to convert word1 to word2.

Integer to Roman

Seven different symbols represent Roman numerals with the following values:

Contains Duplicate

Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

Search a 2D Matrix

You are given an m x n integer matrix matrix with the following two properties:

Substrings of Size Three with Distinct Characters

A string is good if there are no repeated characters.

Second Highest Salary

Table: Employee

Median of Two Sorted Arrays

Given two sorted arrays nums1 and nums2 of size m and n respectively, return the median of the two sorted arrays.

Merge Two Sorted Lists

You are given the heads of two sorted linked lists list1 and list2.

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:

K Closest Points to Origin

Given an array of points where points[i] = [xi, yi] represents a point on the X-Y plane and an integer k, return the k closest points to the origin (0, 0).

Number of Subarrays That Match a Pattern I

You are given a 0-indexed integer array nums of size n, and a 0-indexed integer array pattern of size m consisting of integers -1, 0, and 1.

Sliding Window Maximum

You are given an array of integers nums, there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see...

Best Time to Buy and Sell Stock III

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

House Robber II

You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed. All houses at this place are arranged in...

Find Servers That Handled Most Number of Requests

You have k servers numbered from 0 to k-1 that are being used to handle multiple requests simultaneously. Each server has infinite computational capacity but ca...

Split Message Based on Limit

You are given a string, message, and a positive integer, limit.

Find the Length of the Longest Common Prefix

You are given two arrays with positive integers arr1 and arr2.

LFU Cache

Design and implement a data structure for a Least Frequently Used (LFU) cache.

Binary Tree Cameras

You are given the root of a binary tree. We install cameras on the tree nodes where each camera at a node can monitor its parent, itself, and its immediate chil...

Partition Equal Subset Sum

Given an integer array nums, return true if you can partition the array into two subsets such that the sum of the elements in both subsets is equal or false oth...

Best Time to Buy and Sell Stock with Cooldown

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

Minimum Time Difference

Given a list of 24-hour clock time points in "HH:MM" format, return the minimum minutes difference between any two time-points in the list.

Image Smoother

An image smoother is a filter of the size 3 x 3 that can be applied to each cell of an image by rounding down the average of the cell and the eight surrounding...

Number of Matching Subsequences

Given a string s and an array of strings words, return the number of words[i] that is a subsequence of s.

Sum Root to Leaf Numbers

You are given the root of a binary tree containing digits from 0 to 9 only.

Spiral Matrix

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