963. Minimum Area Rectangle II
You are given an array of points in the X-Y plane points where points[i] = [xi, yi].
Return the minimum area of any rectangle formed from these points, with sides not necessarily parallel to the X and Y axes. If there is not any such rectangle, return 0.
Answers within 10-5 of the actual answer will be accepted.
882. Reachable Nodes In Subdivided Graph
You are given an undirected graph (the “original graph”) with n nodes labeled from 0 to n - 1. You decide to subdivide each edge in the graph into a chain of nodes, with the number of new nodes varying between each edge.
The graph is given as a 2D array of edges where edges[i] = [ui, vi, cnti] indicates that there is an edge between nodes ui and vi in the original graph, and cnti is the total number of new nodes that you will subdivide the edge into. Note that cnti == 0 means you will not subdivide the edge.
To subdivide the edge [ui, vi], replace it with (cnti + 1) new edges and cnti new nodes. The new nodes are x1, x2, …, xcnti, and the new edges are [ui, x1], [x1, x2], [x2, x3], …, [xcnti-1, xcnti], [xcnti, vi].
In this new graph, you want to know how many nodes are reachable from the node 0, where a node is reachable if the distance is maxMoves or less.
Given the original graph and maxMoves, return the number of nodes that are reachable from node 0 in the new graph.
1960. Maximum Product of the Length of Two Palindromic Substrings
You are given a 0-indexed string s and are tasked with finding two non-intersecting palindromic substrings of odd length such that the product of their lengths is maximized.
More formally, you want to choose four integers i, j, k, l such that 0 <= i <= j < k <= l < s.length and both the substrings s[i…j] and s[k…l] are palindromes and have odd lengths. s[i…j] denotes a substring from index i to index j inclusive.
Return the maximum possible product of the lengths of the two non-intersecting palindromic substrings.
A palindrome is a string that is the same forward and backward. A substring is a contiguous sequence of characters in a string.
2111. Minimum Operations to Make the Array K-Increasing
You are given a 0-indexed array arr consisting of n positive integers, and a positive integer k.
The array arr is called K-increasing if arr[i-k] <= arr[i] holds for every index i, where k <= i <= n-1.
For example, arr = [4, 1, 5, 2, 6, 2] is K-increasing for k = 2 because:
- arr[0] <= arr[2] (4 <= 5)
- arr[1] <= arr[3] (1 <= 2)
- arr[2] <= arr[4] (5 <= 6)
- arr[3] <= arr[5] (2 <= 2)
However, the same arr is not K-increasing for k = 1 (because arr[0] > arr[1]) or k = 3 (because arr[0] > arr[3]).
In one operation, you can choose an index i and change arr[i] into any positive integer.
Return the minimum number of operations required to make the array K-increasing for the given k.
311. Sparse Matrix Multiplication
Given two sparse matrices mat1 of size m x k and mat2 of size k x n, return the result of mat1 x mat2. You may assume that multiplication is always possible.
1884. Egg Drop With 2 Eggs and N Floors
You are given two identical eggs and you have access to a building with n floors labeled from 1 to n.
You know that there exists a floor f where 0 <= f <= n such that any egg dropped at a floor higher than f will break, and any egg dropped at or below floor f will not break.
In each move, you may take an unbroken egg and drop it from any floor x (where 1 <= x <= n). If the egg breaks, you can no longer use it. However, if the egg does not break, you may reuse it in future moves.
Return the minimum number of moves that you need to determine with certainty what the value of f is.
Given a binary tree, determine if it is height-balanced.
For this problem, a height-balanced binary tree is defined as:
a binary tree in which the left and right subtrees of every node differ in height by no more than 1.
1031. Maximum Sum of Two Non-Overlapping Subarrays
Given an integer array nums and two integers firstLen and secondLen, return the maximum sum of elements in two non-overlapping subarrays with lengths firstLen and secondLen.
The array with length firstLen could occur before or after the array with length secondLen, but they have to be non-overlapping.
A subarray is a contiguous part of an array.
Given an integer array nums where every element appears three times except for one, which appears exactly once. Find the single element and return it.
You must implement a solution with a linear runtime complexity and use only constant extra space.
807. Max Increase to Keep City Skyline
There is a city composed of n x n blocks, where each block contains a single building shaped like a vertical square prism. You are given a 0-indexed n x n integer matrix grid where grid[r][c] represents the height of the building located in the block at row r and column c.
A city’s skyline is the the outer contour formed by all the building when viewing the side of the city from a distance. The skyline from each cardinal direction north, east, south, and west may be different.
We are allowed to increase the height of any number of buildings by any amount (the amount can be different per building). The height of a 0-height building can also be increased. However, increasing the height of a building should not affect the city’s skyline from any cardinal direction.
Return the maximum total sum that the height of the buildings can be increased by without changing the city’s skyline from any cardinal direction.