Abhishek Sharma

Question You are given an integer array nums with no duplicates. A maximum binary tree can be built recursively from nums using the following algorithm: Create a root node whose value is the maximum value in nums. Recursively build the left subtree on the subarray prefix to the left of the maximum value. Recursively build the right subtree on the subarray suffix to the right of the maximum value. Return the maximum …

[Solved] You are given an integer array nums with no duplicates. A maximum binary tree can be built recursively from nums using the following algorithm: Create a root node whose value is the maximum value in nums. Read More »

Question Given the root of a Binary Search Tree and a target number k, return true if there exist two elements in the BST such that their sum is equal to the given target. Example 1: Input: root = [5,3,6,2,4,null,7], k = 9 Output: true Example 2: Input: root = [5,3,6,2,4,null,7], k = 28 Output: false Constraints: The number of …

[Solved] Given the root of a Binary Search Tree and a target number k, return true if there exist two elements in the BST such that their sum is equal to the given target. Read More »

Question Given the root of a binary tree, return the average value of the nodes on each level in the form of an array. Answers within 10-5 of the actual answer will be accepted. Example 1: Input: root = [3,9,20,null,null,15,7] Output: [3.00000,14.50000,11.00000] Explanation: The average value of nodes on level 0 is 3, on level 1 is 14.5, and on …

[Solved] Given the root of a binary tree, return the average value of the nodes on each level in the form of an array. Answers within 10-5 of the actual answer will be accepted. Read More »

Question Table: Salary +————-+———-+ | Column Name | Type | +————-+———-+ | id | int | | name | varchar | | sex | ENUM | | salary | int | +————-+———-+ id is the primary key for this table. The sex column is ENUM value of type (‘m’, ‘f’). The table contains information about an …

[Solved] Write an SQL query to swap all ‘f’ and ‘m’ values (i.e., change all ‘f’ values to ‘m’ and vice versa) with a single update statement and no intermediate temporary tables. Read More »

Question Table: Cinema +—————-+———-+ | Column Name | Type | +—————-+———-+ | id | int | | movie | varchar | | description | varchar | | rating | float | +—————-+———-+ id is the primary key for this table. Each row contains information about the name of a movie, its genre, and its rating. rating …

[Solved] Write an SQL query to report the movies with an odd-numbered ID and a description that is not “boring”. Read More »

Question Given the root of an n-ary tree, return the postorder traversal of its nodes’ values. Nary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples) Example 1: Input: root = [1,null,3,2,4,null,5,6] Output: [5,6,3,2,4,1] Example 2: Input: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14] Output: [2,6,14,11,7,3,12,8,4,13,9,10,5,1] Constraints: The number of …

[Solved] Given the root of an n-ary tree, return the postorder traversal of its nodes’ values. Nary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples) Read More »

Question Table: World +————-+———+ | Column Name | Type | +————-+———+ | name | varchar | | continent | varchar | | area | int | | population | int | | gdp | int | +————-+———+ name is the primary key column for this table. Each row of this table gives information about the name …

[Solved] A country is big if: it has an area of at least three million (i.e., 3000000 km2), or it has a population of at least twenty-five million (i.e., 25000000). Write an SQL query to report the name, population, and area of the big countries. Read More »

Question Given the root of an n-ary tree, return the preorder traversal of its nodes’ values. Nary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples) Example 1: Input: root = [1,null,3,2,4,null,5,6] Output: [1,3,5,6,2,4] Example 2: Input: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14] Output: [1,2,3,6,7,11,14,4,8,12,5,9,13,10] Constraints: The number of …

[Solved] Given the root of an n-ary tree, return the preorder traversal of its nodes’ values. Nary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples) Read More »

Question In MATLAB, there is a handy function called reshape which can reshape an m x n matrix into a new one with a different size r x c keeping its original data. You are given an m x n matrix mat and two integers r and c representing the number of rows and the number of columns of the wanted reshaped matrix. The reshaped matrix should be filled …

[Solved] In MATLAB, there is a handy function called reshape which can reshape an m x n matrix into a new one with a different size r x c keeping its original data. You are given an m x n matrix mat and two integers r and c representing the number of rows and the number of columns of the wanted reshaped matrix. Read More »

Question Given an integer array nums of 2n integers, group these integers into n pairs (a1, b1), (a2, b2), …, (an, bn) such that the sum of min(ai, bi) for all i is maximized. Return the maximized sum. Example 1: Input: nums = [1,4,3,2] Output: 4 Explanation: All possible pairings (ignoring the ordering of elements) are: 1. (1, 4), (2, 3) -> min(1, 4) + min(2, 3) = 1 …

[Solved] Given an integer array nums of 2n integers, group these integers into n pairs (a1, b1), (a2, b2), …, (an, bn) such that the sum of min(ai, bi) for all i is maximized. Return the maximized sum. Read More »