The Circumference of the Circle Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 8310   Accepted: 4960 Description To calculate the circumference of a circle seems to be an easy task - provided you know its diameter. But what if you don't…

Circle Through Three Points Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 3766   Accepted: 1570 Description Your team is to write a program that, given the Cartesian coordinates of three points on a plane, will find the equation of the…

LINK:Boundary 计算几何确实是弱项 因为好多东西都不太会求 没有到很精通的地步. 做法很多,先说官方题解 其实就是枚举一个点 P 然后可以发现 再枚举一个点 然后再判断有多少个点在圆上显然会超时. 直接考虑求出所有点和\(O,P\)的夹角 因为同弧所对圆周角相等 最后统计有多少个角度相等来做. 一个误区是 两个对称的圆上的点被算在一起了 此时强制利用 第三个点在所在直线的左侧/右侧来消除影响. 正确性显然.复杂度\(n^2\cdot logn\) 一个比较好想好写的做法: 枚举到第三…

已知P1.P2.P3,求点O 算法:三点不在一条直线上时,通过连接任意两点,作中垂线.任意两条中垂线的交点是圆心.…

Squares Time Limit: 3500MS   Memory Limit: 65536K Total Submissions: 18493   Accepted: 7124 Description A square is a 4-sided polygon whose sides have equal length and adjacent sides form 90-degree angles. It is also a polygon such that rotating abou…

传送门:https://www.luogu.org/problemnew/show/P1027 题意: 图中有n个城市,每个城市有4个机场在矩形的四个顶点上.一个城市间的机场可以通过高铁通达,不同城市间要通过飞机.现在问从s到t城市最少需要多少的费用. 思路: 已知矩形的三个顶点,可以用勾股定理确定斜边后,利用平行四边形原理——两对对角顶点的x之和是相同的,y之和也是相同的得到第四个顶点.然后用求最短路的dji即可. #include <algorithm> #include <iter…

在看组合数学,看到逆序列这个概念.于是YY了一道题:已知逆序列,求出原序列. 例子: 元素个数 n = 8 逆序列 a={5,3,4,0,2,1,1,0} 则有原序列 p={4,8,6,2,5,1,3,7} 思路蛮简单的,但是复杂度是O(2*N*lgN)的,不知道有没有O(N)的算法. bit维护点[1,i]的所有空位置,则可以知道这个数列是单调递增的. 每一次去找满足i的逆序列ai+1的最左的空位pos(因为考虑不包括当前位置的空位数),然后更新[pos-1,n]所有空位-1(在pos处插入i…

已知段地址为0001H,仅通过变化偏移地址寻址,则CPU的寻址范围是? 物理地址 = 段地址×16 + 偏移地址 所以物理地址的范围是[16×1H+0H, 16×1H+FFFFH] 也就是[10H×1H+0H, 10H×1H+FFFFH] 所以CPU的寻址范围是[10H, 1000FH]…

Wall Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 28462   Accepted: 9498 Description Once upon a time there was a greedy King who ordered his chief Architect to build a wall around the King's castle. The King was so greedy, that he wo…

Pyramids Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 2718   Accepted: 886   Special Judge Description Recently in Farland, a country in Asia, a famous scientist Mr. Log Archeo has discovered ancient pyramids. But unlike those in Egyp…