391. 完美矩形 我们有 N 个与坐标轴对齐的矩形, 其中 N > 0, 判断它们是否能精确地覆盖一个矩形区域. 每个矩形用左下角的点和右上角的点的坐标来表示.例如, 一个单位正方形可以表示为 [1,1,2,2]. ( 左下角的点的坐标为 (1, 1) 以及右上角的点的坐标为 (2, 2) ). 示例 1: rectangles = [ [1,1,3,3], [3,1,4,2], [3,2,4,4], [1,3,2,4], [2,3,3,4] ] 返回 true.5个矩形一起可以精确地覆盖一个…

完美矩形 我们有 N 个与坐标轴对齐的矩形, 其中 N > 0, 判断它们是否能精确地覆盖一个矩形区域. 每个矩形用左下角的点和右上角的点的坐标来表示.例如, 一个单位正方形可以表示为 [1,1,2,2]. ( 左下角的点的坐标为 (1, 1) 以及右上角的点的坐标为 (2, 2) ). 示例 1: rectangles = [ [1,1,3,3], [3,1,4,2], [3,2,4,4], [1,3,2,4], [2,3,3,4] ] 返回 true.5个矩形一起可以精确地覆盖一个矩形区域.…

507. 完美数 对于一个 正整数,如果它和除了它自身以外的所有正因子之和相等,我们称它为"完美数". 给定一个 整数 n, 如果他是完美数,返回 True,否则返回 False 示例: 输入: 28 输出: True 解释: 28 = 1 + 2 + 4 + 7 + 14 提示: 输入的数字 n 不会超过 100,000,000. (1e8) class Solution { public boolean checkPerfectNumber(int num) { if (num %…

492. 构造矩形 作为一位web开发者, 懂得怎样去规划一个页面的尺寸是很重要的. 现给定一个具体的矩形页面面积,你的任务是设计一个长度为 L 和宽度为 W 且满足以下要求的矩形的页面.要求: 你设计的矩形页面必须等于给定的目标面积. 宽度 W 不应大于长度 L,换言之,要求 L >= W . 长度 L 和宽度 W 之间的差距应当尽可能小. 你需要按顺序输出你设计的页面的长度 L 和宽度 W. 示例: 输入: 4 输出: [2, 2] 解释: 目标面积是 4, 所有可能的构造方案有 [1,4]…

85. 最大矩形 给定一个仅包含 0 和 1 的二维二进制矩阵,找出只包含 1 的最大矩形,并返回其面积. 示例: 输入: [ ["1","0","1","0","0"], ["1","0","1","1","1"], ["1","1","1",&q…

Given N axis-aligned rectangles where N > 0, determine if they all together form an exact cover of a rectangular region. Each rectangle is represented as a bottom-left point and a top-right point. For example, a unit square is represented as [1,1,2,2…

Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination should be a unique set of numbers. Ensure that numbers within the set are sorted in ascending order. Example 1…

Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrome you can find by performing this transformation. For example: Given "aacecaaa", return "aaacecaaa&qu…

Given a 2D board and a list of words from the dictionary, find all words in the board. Each word must be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically neighboring. The same le…

Design a data structure that supports the following two operations: void addWord(word)bool search(word) search(word) can search a literal word or a regular expression string containing only letters a-z or .. A . means it can represent any one letter.…