Given the root of a binary search tree with distinct values, modify it so that every node has a new value equal to the sum of the values of the original tree that are greater than or equal to node.val.
leetcode-1114-Print-in-Order
Suppose we have a class:
1 | public class Foo { |
leetcode-406-Queue-Reconstruction-by-Height
Suppose you have a random list of people standing in a queue. Each person is described by a pair of integers (h, k), where h is the height of the person and k is the number of people in front of this person who have a height greater than or equal to h. Write an algorithm to reconstruct the queue.
leetcode-535-encode-and-decode-tinyurl
TinyURL is a URL shortening service where you enter a URL such as https://leetcode.com/problems/design-tinyurl and it returns a short URL such as http://tinyurl.com/4e9iAk.
Design the encode and decode methods for the TinyURL service. There is no restriction on how your encode/decode algorithm should work. You just need to ensure that a URL can be encoded to a tiny URL and the tiny URL can be decoded to the original URL.
leetcode-595-Big-Countries
There is a table World
leetcode-807-Max-Increase-to-Keep-City-Skyline
In a 2 dimensional array grid, each value grid[i][j] represents the height of a building located there. We are allowed to increase the height of any number of buildings, by any amount (the amounts can be different for different buildings). Height 0 is considered to be a building as well.
leetcode-832-Flipping-an-Image
Given a binary matrix A, we want to flip the image horizontally, then invert it, and return the resulting image.
了解web及网络基础
在浏览器中输入URL后 信息会被送往某处，Web浏览器从Web服务端获取文件资源等信息，从而显示出web页面。
像这种通过发送请求获取服务器资源的web浏览器，都可以被称为客户端。web使用一种名为HTTP的协议作为规范完成从客户端到服务器端一系列的运作流程。