优雅的暴力. 设三个点为 \((i,j,k)\),则有 \(6\) 个未知数即 \(x_i,x_j,x_k,y_i,y_j,y_k\).又因为有 \(2\) 条关于这 \(6\) 个未知数的方程 \(ij=jk,ij=ik\),所以一定能通过枚举其中的 \(4\) 个量来求解,时间复杂度 \(O(n^4)\). 而这个 \(O(n^4)\) 的暴力是肉眼可见的跑不满( 考虑先枚举点 \(i\),则有以下四种情况: 解得 \(x=a,y=a-b\). 其中,\(a,x>0,0\le b,y \le…

Almost equilateral triangles It is easily proved that no equilateral triangle exists with integral length sides and integral area. However, the almost equilateral triangle 5-5-6 has an area of 12 square units. We shall define an almost equilateral tr…

You will be given N points on a circle. You must write a program to determine how many distinctequilateral triangles can be constructed using the given points as vertices.The gure below illustrates an example: (a) shows a set of points, determined by…

本章问题 1.Is the following statement legal?If so,what does it do? (下面的语句是否合法,如果合法,它做了什么) 3 * x * x - 4 * x + 6; answer:It is legal,but it doesn't affect the program's state,None of the operators involved(有关) have any side effects and the result that is…

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=2119 11178 - Morley's Theorem Time limit: 3.000 seconds Problem DMorley’s TheoremInput: Standard Input Output: Standard Output Morley’s theorem stat…

之前转载了一篇博客http://blog.sina.com.cn/s/blog_6163bdeb0102dvay.html,讲Matlab网格划分程序Distmesh,看了看程序,感觉程序写得有很多值得学的地方,所以又自己重新看了一看,加了一些注释,最后再总结一下学到的东西吧. 源代码的地址已经改变,如下http://people.sc.fsu.edu/~jburkardt/m_src/distmesh/distmesh.html.程序给出了20个划分的例子,文件名为p1_demo.m~p20_…

描述 https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=23&page=show_problem&problem=2119 Morley定理:作三角形ABC每个内角的三等分线,相交形成三角形DEF,则三角形DEF是等边三角形. 给出三角形的三个顶点ABC的坐标,求出DEF的坐标. 11178 - Morley's Theorem Time limit: 3.000 s…

Problem D Morley's Theorem Input: Standard Input Output: Standard Output Morley's theorem states that that the lines trisecting the angles of an arbitrary plane triangle meet at the vertices of an equilateral triangle. For example in the figure below…

Morley’s Theorem Input: Standard Input Output: Standard Output Morley’s theorem states that that the lines trisecting the angles of an arbitrary plane triangle meet at the vertices of an equilateral triangle. For example in the figure below the tri-s…

开始了解响应式图片 响应式,根据屏幕尺寸和分辨率的设备上都能良好工作以及其他特性的图片,接下来考虑怎样创建自适应得图片,专注于img元素,完成自适应. 分辨率切换,不同的尺寸 <img srcset="elva-fairy-320w.jpg 320w, elva-fairy-480w,jpg 480w, evla-fairy-880w,jpg 800w" sizes="(max-width: 320px) 280px, (max-width: 480px) 440px,…