Can you solve this real interview question? 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.

An island is surrounded by water and is formed by connecting adjacent…

Can you solve this real interview question? Letter Combinations of a Phone Number - Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any order.

A mapping of…

Can you solve this real interview question? Kth Smallest Element in a BST - Given the root of a binary search tree, and an integer k, return the kth smallest value (1-indexed) of all the values of the nodes in the tree.

 

Example 1:

[https://assets.le…

Can you solve this real interview question? Perfect Squares - Given an integer n, return the least number of perfect square numbers that sum to n.

A perfect square is an integer that is the square of an integer; in other words, it is the product of some…

Can you solve this real interview question? Sort Colors - You are given an array nums with n objects colored red, white, or blue, sort them in-place [https://en.wikipedia.org/wiki/In-place_algorithm] so that objects of the same color are adjacent, with the…

Can you solve this real interview question? Lowest Common Ancestor of a Binary Tree - Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.

According to the definition of LCA on Wikipedia [https://en.wikipedia.org/wi…

Can you solve this real interview question? Subarray Sum Equals K - Given an array of integers nums and an integer k, return the total number of subarrays whose sum equals to k.

A subarray is a contiguous non-empty sequence of elements within an array.
…

Can you solve this real interview question? 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 otherwise.

 

Example 1:…

Can you solve this real interview question? Search a 2D Matrix II - Write an efficient algorithm that searches for a value target in an m x n integer matrix matrix. This matrix has the following properties:

* Integers in each row are sorted in ascending…

Can you solve this real interview question? Find All Anagrams in a String - 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.

 

Example 1:


Input: s = "cbaebabacd", p = "abc"…

Can you solve this real interview question? 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, bi] indicates that you must take course…

Can you solve this real interview question? Longest Increasing Subsequence - Given an integer array nums, return the length of the longest strictly increasing subsequence.

 

Example 1:


Input: nums = [10,9,2,5,3,7,101,18]
Output: 4
Explanation: The longest…

Can you solve this real interview question? Sort List - Given the head of a linked list, return the list after sorting it in ascending order.

 

Example 1:

[https://assets.leetcode.com/uploads/2020/09/14/sort_list_1.jpg]


Input: head = [4,2,1,3]
Output:…

Can you solve this real interview question? Word Break - Given a string s and a dictionary of strings wordDict, return true if s can be segmented into a space-separated sequence of one or more dictionary words.

Note that the same word in the dictionary may…

Can you solve this real interview question? 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 cover all the intervals in the input.…

Can you solve this real interview question? Insert Delete GetRandom O(1) - Implement the RandomizedSet class:

* RandomizedSet() Initializes the RandomizedSet object.
* bool insert(int val) Inserts an item val into the set if not present. Returns true if…

Can you solve this real interview question? 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.

 

Example 1:

[https://assets.leetcode.com/uploads/2020/11/26/max1grid.jpg]…

Can you solve this real interview question? Linked List Cycle II - Given the head of a linked list, return the node where the cycle begins. If there is no cycle, return null.

There is a cycle in a linked list if there is some node in the list that can be…

Can you solve this real interview question? Find First and Last Position of Element in Sorted Array - 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…

Can you solve this real interview question? 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.

Construct a deep copy [https://…

Can you solve this real interview question? 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.

 

Example 1:

[https://assets.leetcode.com/uploads/2020/10/03/remove_ex1.jpg]…