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问题 I started out trying to style <Link> elements from react-router . <Link style={{display: 'flex'}}>...</Link> but it seems like it strips the display CSS property specifically. Does anyone know why and how to fix it? I get the same problems with <a style={{display: 'flex', marginTop: '10px'}}>Test link</a> (Result: Only margin-top: 10px is applied) EDIT: For future reference, as I see this page still gets some views: I really tried using multiple vendor-specific display CSS attributes, and not

问题 Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). Question link is here The recursion method need to traverse the tree twice. But one of the comment provided a solution used a technique called 'Null check'. I can't understand why in this way can we avoid checking the tree twice? Here is his code in C++: bool isSymmetric(TreeNode* root) { if (!root) return true; return isSymmetric(root->left, root->right); } bool isSymmetric(TreeNode* t1, TreeNode*

问题 I searched a lot about it. All the articles i get include SQLAlchemy and none of them deal with mysql. I am working with flask and i have a database in mysql and i need to display the data in pages. Like 1000 images, per page 10 so 100 pages. In mysql we can do pagination with the help of limit. And the routes can be: @app.route('/images', defaults={'page':1}) @app.route('/images/page/<int:page>') I need to ask is this all that is needed for pagination? or am i forgetting something important

问题 I am drawing ECG graphs using C# Graphics. I draw the curve using drawlines method. however line joints look broken. I tried all available options of smoothing mode and capstyle, none helps. here is sample graph1 and sample graph2 code is below: private void DrawCurve(Graphics g, cPoint[] data) { List<Point> ps = new List<Point>(); for (int i = 0; i < data.Length - 1; i++) { int x = data[i].x; int y = data[i].y; if (x > 0 && x < (Width)) { ps.Add(new Point(x, y)); } else if (x > Width) {

问题 I am stuck at this problem. I think it is equivalent to show 2m choose m is big theta of 4 to the power n, but still find difficult to prove it. Thanks of @LutzL's suggestion. I thought of stirling's approximation before. 回答1: The O -part should be easy. Choosing exactly n /2 elements out of n is a special case of choosing arbitrary combinations out of n elements, i.e. deciding for each of these n elements whether to choose it or not. The Ω -part is harder. In fact, plotting 4n / binomial(2 n

问题 I am programming with Swift in Xcode (MacBook Air 2015) and I want to change my Swift version from 5 to 4. How to do that? 回答1: Project ► (Select Your Project Target) ► Build Settings ► (Type 'swift_version' in the Search bar) Swift Compiler Language ► Swift Language Version ► Click on Language list Here you can change your version. 来源： https://stackoverflow.com/questions/56894082/how-to-change-swift-version-from-5-to-4-in-xcode

问题 I want to match the userid number in a url string that's usually after a id= or /user/ Examples: http://dummy.url/url/path/id=7623 http://dummy.url/url/path/user/8743 http://dummy.url/url/path/user/56 http://dummy.url/url/path=88772/user/890&more=87273&variables&here=76233 http://dummy.url/url/path/id=2818372 I need to match 7623, 8743, 56, 890, 2818372 I haven't tried much on this as I'm a complete noob at regex and I only know how to mach numbers, all numbers, so if the url has any it will

问题 My dataframe looks like this: ID Class 0 9 1 8 1 6 2 6 2 2 3 15 3 1 3 8 What I would like to do is merging rows with same ID value in a way below: ID Class1 Class2 Class3 0 9 1 8 6 2 6 2 3 15 1 8 So for each ID which exists more than once, I want to create new column(s) and move values from rows to those columns. What is the fastest way to do this? I tried using groupby but it didn't give me appriopate results. 回答1: Use set_index with cumcount for new columns, reshape by unstack and last

问题 I am not sure what I am exactly doing here so please give some advise and forgive the mistakes. I have a image byte[] called idCardImage and I did the following to convert it to a String: String s = new String(idCardImage); And it prints out like this: data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAEHUlEQVQ4TzWUW49VRRCFv6rq3ufMmTNn.... Did some search online and it seems this image is in a png format with base 64 encoded. What I need to do is to convert it to a jpeg

问题 I'm trying to create my first widget. I run the app through eclipse, and it launches fine. But when I try to add the widget from the widgets menu to the home screen I get a toast that says: App isn't installed When I look at the logcat I see this error: 05-15 18:35:10.533: E/Launcher(851): Error: appWidgetId (EXTRA_APPWIDGET_ID) was not returned from the \widget configuration activity. I don't have a configuration activity at all, and as far as I understood from the developer's site, it's not