Given a binary tree with N nodes, each node has a different value from {1, ..., N}. A node in this binary tree can be flipped by swapping the left child and the right child of that node. Consider the

本文将演示使用第三方类库中，将服务器返回的JSON映射为实例对象。 首先确保在项目中已经安装了所需的第三方库。 点击【Podfile】,查看安装配置文件。 1 platform :ios, ’12.0’ 2 use_frameworks! 3 4 target ‘DemoApp‘ do 5 source ‘https://github.com/CocoaPods/Specs.gi

There are a row of n houses, each house can be painted with one of the k colors. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two ad

Given a string, determine if a permutation of the string could form a palindrome. For example, "code" -> False, "aab" -> True, "carerac" -> True. Hint: Consider the palindromes of odd vs even length.

import UIKit class ViewController: UIViewController{ override func viewDidLoad() { super.viewDidLoad() //创建DatePicker let datePicker = UIDatePicker() //设置位置

添加AlertController import UIKit var imageView:UIImageView! class ViewController: UIViewController { override func viewDidLoad() { super.viewDidLoad() let button = UIButton(frame: CG

import UIKit class ViewController: UIViewController{ var stepper:UIStepper! var label:UILabel! override func viewDidLoad() { super.viewDidLoad() //创建Stepper steppe

import UIKit class ViewController: UIViewController,UIPickerViewDataSource,UIPickerViewDelegate { var pickerView:UIPickerView! override func viewDidLoad() { super.viewDidLoad()

本文将演示日期和时间类型的扩展方法。 首先确保在项目中已经安装了所需的第三方库。 点击【Podfile】,查看安装配置文件。 1 platform :ios, ‘12.0’ 2 use_frameworks! 3 4 target ‘DemoApp‘ do 5 source ‘https://github.com/CocoaPods/Specs.git‘ 6 7

Given an array of citations sorted in ascending order (each citation is a non-negative integer) of a researcher, write a function to compute the researcher‘s h-index. According to the definition of h-

Given an array of citations (each citation is a non-negative integer) of a researcher, write a function to compute the researcher‘s h-index. According to the definition of h-index on Wikipedia: "A sci

You are playing the following Bulls and Cows game with your friend: You write down a number and ask your friend to guess what the number is. Each time your friend makes a guess, you provide a hint tha

本文将演示对基本类型：Int、String、Array、Dictionary、Date的扩展。 首先确保在项目中已经安装了所需的第三方库。 点击【Podfile】,查看安装配置文件。 1 platform :ios, ‘12.0‘ 2 use_frameworks! 3 4 target ‘DemoApp‘ do 5 source ‘https://github.com/Coco

import UIKit class ViewController: UIViewController{ override func viewDidLoad() { super.viewDidLoad() //SwipeGestureRecognizer：滑动手势 let swipe = UISwipeGestureRecognizer(ta

import UIKit class ViewController: UIViewController{ override func viewDidLoad() { super.viewDidLoad() let view = UIView(frame: CGRect(x: 150, y: 250, width: 100, height: 100))

import UIKit class ViewController: UIViewController{ override func viewDidLoad() { super.viewDidLoad() let browserToolbar = UIToolbar(frame: CGRect(x: 0, y: 20, width: 320, height

WKWebView加载页面 import UIKit import WebKit class ViewController: UIViewController{ var webView : WKWebView! var loadType : UISegmentedControl! override func viewDidLoad() { super.vie

1.加速传感器可以监听到x,y,z三个方向的加速度，步骤如下： (1)实例化CMMotionManager类 (2)向CMMotionManager的accelerometerUpdateInterval属性中设置通知间隔时间值 (3)使用PerationQueeu.current建立一个监听队列 (4)使用startAccelerometerUpfates方法更新监听队列，并设置回调函数用于接受

import UIKit class ViewController: UIViewController{ var activityIndicator:UIActivityIndicatorView! override func viewDidLoad() { super.viewDidLoad() //设置环形滚动条的样式 activ

本文将演示视图类型（UIView）在frame/约束/旋转/缩放/圆角/各种手势等一些实用扩展方法。 首先确保在项目中已经安装了所需的第三方库。 点击【Podfile】,查看安装配置文件。 1 platform :ios, ‘12.0‘ 2 use_frameworks! 3 4 target ‘DemoApp‘ do 5 source ‘https://github.com/C

本文将演示图像和图像视图在下载、压缩、裁剪方面的扩展。 首先确保在项目中已经安装了所需的第三方库。 点击【Podfile】,查看安装配置文件。 1 platform :ios, ‘12.0‘ 2 use_frameworks! 3 4 target ‘DemoApp‘ do 5 source ‘https://github.com/CocoaPods/Specs.git‘ 6

Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. The update(i, val) function modifies nums by updating the element at index i to val. Example: Give

Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2). The above rectangle (with the red border)

创建UITablView import UIKit class ViewController: UIViewController,UITableViewDataSource,UITableViewDelegate{ var Names = ["A","B","C","D","E","F"] var tableView:UITableView! override

本文将演示图像加载Loading动画效果的自定义和缓存。 首先确保在项目中已经安装了所需的第三方库。 点击【Podfile】,查看安装配置文件。 1 platform :ios, ‘12.0‘ 2 use_frameworks! 3 4 target ‘DemoApp‘ do 5 source ‘https://github.com/CocoaPods/Specs.git‘ 6

Write a program to find the nth super ugly number. Super ugly numbers are positive numbers whose all prime factors are in the given prime list primes of size k. Example: Input: n = 12, = Output: 32

Given n balloons, indexed from 0 to n-1. Each balloon is painted with a number on it represented by array nums. You are asked to burst all the balloons. If the you burst balloon i you will get nums[le

本文将演示快速计算字符串中的各种数学表达式。 Gihub项目：【DDMathParser】 下载并解压该项目。将文件夹【MathParser】算术解析包，拖动到自己的项目中。 点击【Finish】完成文件拖动。 在导入的项目中，【MathParser】->【Info.plist】信息列表上鼠标右键 ->【Delete】->【Move to Trash】，删除该配置文件，只保留该文件夹中的代码文件。

For an undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a rooted tree. Among all possible rooted trees, those with minimum height are called min

Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one a