CF553C Love Triangles】的更多相关文章

题目链接 题意:给定n个点,给出一些边权为0/1的边,构造完全图,满足对于任何一个三元环,三条边权和为奇.求符合条件的完全图数量,对\(1e9+7\)取模. 分析:其实原题给定的边权是love/hate,love即1,hate即0. 所以对于三元环而言,只存在"爱爱爱"或"爱恨恨". 如果我们按此讨论点与点之间的关系,我们会想到什么? 敌人的敌人就是朋友,朋友的朋友还是朋友. 那么这道题就和[BOI2003]团伙的描述有些类似了. 我们显然可以用到并查集. 团伙那题…
Tyher推的好题. 题意就是给你一些好边一些坏边,其他边随意,让你求符合好坏坏~,或者只包含好好好的三元环的无向图个数. 坏坏的Tyher的题意是这样的. 再翻译得更加透彻一点就是:给你一些0(好边)边和1(坏边)边,让你求只包含011或者000的三元环的图的个数. 强强的zsy说:"Tyher你好坏啊!这不就是求合法的二分图个数嘛." 容易发现满足题目条件的图一定是只含有偶环(这里是边权和为偶数)的图,那不就是二分图嘛,于是只要统计一下1边相连的联通块个数k,答案就是\(2^{k-…
From: http://www.geeksforgeeks.org/find-number-of-triangles-possible/ Given an unsorted array of positive integers. Find the number of triangles that can be formed with three different array elements as three sides of triangles. For a triangle to be…
Description It is always very nice to have little brothers or sisters. You can tease them, lock them in the bathroom or put red hot chili in their sandwiches. But there is also a time when all meanness comes back! As you know, in one month it is Chri…
Triangles Time Limit:1000MS     Memory Limit:64000KB     64bit IO Format:%lld & %llu Submit Status Practice ACdream 1067 Description 已知一个圆的圆周被  N 个点分成了 N 段等长圆弧,求任意取三个点,组成锐角三角形的个数. Input 多组数据. 每组数据一个N (N ≤  1000000). Output 对于每组数据,输出不同锐角三角形的个数. Sample…
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…
Fighting for Triangles 题目连接: http://codeforces.com/gym/100015/attachments Description Andy and Ralph are playing a two-player game on a triangular board that looks like the following: 1 2 3 4 5 7 8 6 9 10 11 13 14 16 17 12 15 18 At each turn, a playe…
C. Love Triangles Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/553/problem/C Description There are many anime that are about "love triangles": Alice loves Bob, and Charlie loves Bob as well, but Alice hates Charlie.…
D. Vanya and Triangles Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/552/problem/D Description Vanya got bored and he painted n distinct points on the plane. After that he connected all the points pairwise and saw that as…
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…