题目链接:http://codeforces.com/gym/102279/problem/H 大致题意: 你在一个定点,你有个长度为R的钩子,有n个东西在其他点处,问你能勾到的东西的数量是多少? 思路:明明一道几何题,罗老板居然用gcd巧妙的A了,真是太强了.如果一件物品挡住了另一件物品,那么它是勾不到的. 首先将所有距离在R的点都拎出来,然后对于给定点进行极角排序,最后俩俩相邻比较即可确定答案. AC代码: #include<cmath> #include<cstdio> #i…

B. Beggin' For A Node time limit per test2.0 s memory limit per test256 MB inputstandard input outputstandard output This is an interactive problem Low_ has a beautiful tree, which he keeps very carefully. A tree is a tree, but mathematically, it cou…

C. Paint Tree time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a tree with n vertexes and n points on a plane, no three points lie on one straight line. Your task is to paint…

Partial Tree Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/598/problem/C Description You are given the set of vectors on the plane, each of them starting at the origin. Your task is to find a pair of vectors with the mini…

n=40的01串,求有多少m=40的01串中包含它,包含的定义是存在子串有至多一个字符不相同 600组n=15的数据 15组n=40的数据,所以我们只能支持n^5的算法. 陷入两个比较有意思的坑: 1 如果手动构建fail树,建立两个并行的串,左串代表当前未使用那一个可以不相同的字符的名额,右串代表已经使用了这个名额,那么按照bfs m步的想法,左串可以通过“使用名额”到达右串,也可以通过“不使用名额”走一个fail,而右串一旦失配,只能在右串的对应位置进行fail.这样跑一遍矩阵乘法,复杂度是…

Problem Description Pony is the boss of a courier company. The company needs to deliver packages to n offices numbered from 1 to n. Especially, the s-th office is the transfer station of the courier company. There are x ordinary two-way roads and y o…

B. Drazil and Tiles 题目连接: http://codeforces.com/contest/516/problem/B Description Drazil created a following problem about putting 1 × 2 tiles into an n × m grid: "There is a grid with some cells that are empty and some cells that are occupied. You s…

传送门 D. Drazil and Tiles time limit per test 2 seconds memory limit per test 256 megabytes Drazil created a following problem about putting 1 × 2 tiles into an n × m grid: "There is a grid with some cells that are empty and some cells that are occupie…

A. Anton and Polyhedrons time limit per test:2 seconds memory limit per test:256 megabytes input:standard input output:standard output Anton's favourite geometric figures are regular polyhedrons. Note that there are five kinds of regular polyhedrons:…

https://codeforces.com/contest/1131/problem/D 题意 给你一个n*m二维偏序表,代表x[i]和y[j]的大小关系,根据表构造大小分别为n,m的x[],y[],使得两个数组中最大的数尽量小 题解 按照偏序表,构造出从小到大的拓扑图 如何解决相等的数的偏序关系? 用并查集缩点后再进行拓扑排序 如何解决最大的数最小? 只需要使得同一层的数相同就行,可以一批处理栈中的元素,对于一批栈中的元素产生的新点,先放进一个容器里,然后等到这批栈清空了,再把这个容器中的点…