不妨设$r1\le r2\le r3$,令$f(\alpha)=E(S_{\Delta}ABC)$,其中AB坐标分别为$(r_{1},0)$和$(r_{2}\cos \alpha,r_{2}\sin \alpha)$,C在原点为圆心.$r_{3}$为半径的圆上,那么有答案$ans=\lim_{n\to\infty}\limits\frac{\sum_{i=1}^{n}f(\frac{2\pi i}{n})}{n}$,而由于答案误差可以较大,因此n取1000左右即可 考虑求$f(\alpha)$,…

Introduction The system locale specifies the language settings of system services and user interfaces. The keyboard layout settings control the layout used on the text console and graphical user interfaces. These settings can be made by modifying the…

<activity android:name="xxxActivity" android:configChanges="keyboard|keyboardHidden|orientation|screenSize" android:launchMode="singleTask" ---launchMode为singleTask的时候,通过Intent启到一个Activity,如果系统已经存在一个实例,系统就会将请求发送到这个实例上,但这个时…

catalogue . 引言 . Device Class Definition for Human Interface Devices (HID) . USB HID Report Descriptors . arduino USB Keyboard definition . USB Host Shield for Arduino分类 . USB Host Shield for Arduino datasheet . USB Host Library Rev.2.0 . USB Keyboar…

imx6需要添加4x4的矩阵键盘.本文记录添加方法. 参考链接 http://processors.wiki.ti.com/index.php/TI-Android-JB-PortingGuide http://blog.sina.com.cn/s/blog_54aa47930102vesb.html http://blog.csdn.net/shell_albert/article/details/46801091 http://www.kikikoo.com/uid-20768928-id-…

time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Santa Claus decided to disassemble his keyboard to clean it. After he returned all the keys back, he suddenly realized that some pairs of ke…

题目链接: 传送门 Broken Keyboard #include<bits/stdc++.h> using namespace std; char str[100010]; int main() { while(scanf("%s",str)!=EOF) { deque<int > q; int i=0; while(str[i]=='['||str[i]==']') i++; q.push_front(i); while(str[i]) { if(str[…

Modifier keys are specified as `<c-x>`, `<m-x>`, and `<a-x>` for ctrl+x, meta+x, and alt+x respectively. See the next section for how to customize these bindings. Once you have Vimium installed, you can see this list of key bindings at a…

/*数组形式描述链表:链表不一定要用指针. 题目链接:UVa 11988 Broken Keyboard 题目大意: 小明没有开屏幕输入一个字符串,电脑键盘出现了问题会不定时的录入 home end 两个键, 我们知道如果录入home则将光标定位到字符首,如果录入end则是将光标定位到字符尾.现 在让你输出这段坏了文本. 表示:home => '[' , end => ']' 举例: input: hello[_Tom_]! output: _Tom_hello! 解题思路: 数组中频繁移动元…

/*实践再次说明ch=getchar()的速度非常慢*/ /*大水题,不解释*/ #include<stdio.h> #include<string.h> int main() { int i,j,n,count; ]; ]; j=; ; i<=; i++) { ) j=; a[i]=j; j++; } a[]=; a[]=; a[]=; a[]=; a[]=; a[]=; a[]=; a[]=; a[]=; scanf("%d",&n); get…