Cool Points We have a circle of radius R and several line segments situated within the circumference of this circle. Let’s define a cool point to be a point on the circumference of this circle so that the line segment that is formed by this point and…

We have a circle of radius R and several line segments situated within the circumference of this circle. Let’s define a cool point to be a point on the circumference of this circle so that the line segment that is formed by this point and the centre…

UVA 10869 - Brownie Points II 题目链接 题意:平面上n个点,两个人,第一个人先选一条经过点的垂直x轴的线.然后还有一个人在这条线上穿过的点选一点作垂直该直线的线,然后划分出4个象限,第一个人得到分数为1.3象限,第二个人为二四象限.问第一个个人按最优取法,能得到最小分数的最大值,和这个值下还有一个人的得分可能情况 思路:树状数组,能够枚举一点,假设能求出右上和左下点的个数就好办了,其有用一个树状数组,把y坐标离散化掉,然后记录进来,然后把点按x从左往右,每次删掉点后…

传送门:Cool Points 题意:给一个圆心为原点的圆和一些线段,问所有线段两端点与圆心连线构成的角度总和占总360度的百分比. 分析:首先将所有线段的两端点变成极角,然后排序(范围[-PI,PI],即从x轴负方向逆时针转一圈),如果某一线段极角值之差大于PI,构成的角度值肯定不是<AOB,而是<AOX+<XOB.因此处理好这种情况,从x轴负向走一圈计值即可. #include <algorithm> #include <cstdio> #include &l…

Dog Distance [题目链接]Dog Distance [题目类型]几何 &题解: 蓝书的题,刘汝佳的代码,学习一下 &代码: // UVa11796 Dog Distance // Rujia Liu #include<cstdio> #include<cmath> #include<algorithm> using namespace std; const double eps = 1e-8; int dcmp(double x) { if(…

链接: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=3122 题意: 有一根长度为n的木条,随机选k个位置把它们切成k+1段小木条.求这些小木条能组成一个多边形的概率. 分析: 不难发现本题的答案与n无关.在一条直线上切似乎难以处理,可以把直线接成一个圆,多切一下,即在圆上随机选k+1个点,把圆周切成k+1段.根据对称性,两个问题的答案…

链接: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=2321 题意: 在[-a,a]*[-b,b]区域内随机取一个点P,求以(0,0)和P为对角线的长方形面积大于S的概率(a,b>0,S≥0).例如a=10,b=5,S=20,答案为23.35%. 分析: 根据对称性,只需要考虑[0,a]*[0,b]区域取点即可.面积大于S,即xy…

 Lining Up  ``How am I ever going to solve this problem?" said the pilot. Indeed, the pilot was not facing an easy task. She had to drop packages at specific points scattered in a dangerous area. Furthermore, the pilot could only fly over the area on…

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…

UVA 11665 随便给12的找了一道我没做过的几何基础题.这题挺简单的,不过uva上通过率挺低,通过人数也不多. 题意是要求给出的若干多边形组成多少个联通块.做的时候要注意这题是不能用double浮点类型的,然后判多边形交只需要两个条件,存在边规范相交,或者存在一个多边形上的顶点在另一个多边形上或者在多边形内. 代码如下: #include <cstdio> #include <cstring> #include <iostream> #include <al…