B. Clique Problem time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The clique problem is one of the most well-known NP-complete problems. Under some simplification it can be formulated as f…

传送门 D. Clique Problem time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The clique problem is one of the most well-known NP-complete problems. Under some simplification it can be formulated…

B - Clique Problem 题目大意:给你坐标轴上n个点,每个点的权值为wi,两个点之间有边当且仅当 |xi - xj| >= wi + wj, 问你两两之间都有边的最大点集的大小. 思路:其实问题能转换为一堆线段问你最多能挑出多少个线段使其两两不相交.. 对于一个点来说可以变成[x - wi, x + wi]这样一条线段.. 然后贪心取就好啦. #include<bits/stdc++.h> #define LL long long #define fi first #def…

B. Clique Problem time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The clique problem is one of the most well-known NP-complete problems. Under some simplification it can be formulated as f…

Codeforces Round #296 (Div. 1)C. Data Center Drama Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/528/problem/C Description The project of a data center of a Big Software Company consists of n compu…

题目链接:Codeforces Round #367 (Div. 2) C. Hard problem 题意: 给你一些字符串,字符串可以倒置,如果要倒置,就会消耗vi的能量,问你花最少的能量将这些字符串排成字典序 题解: 当时1点过头太晕了,看错题了,然后感觉全世界都会,就我不会,- -!结果就是一个简单的DP, 设dp[i][0]表示第i个字符串不反转的情况,dp[i][1]表示第i个字符串反转的情况 状态转移方程看代码 #include<bits/stdc++.h> #define F(…

Codeforces Round #603 (Div. 2) A. Sweet Problem A. Sweet Problem time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You have three piles of candies: red, green and blue candies: the first pile…

Hard problem 题目链接: http://codeforces.com/contest/706/problem/C Description Vasiliy is fond of solving different tasks. Today he found one he wasn't able to solve himself, so he asks you to help. Vasiliy is given n strings consisting of lowercase Engl…

http://codeforces.com/contest/528/problem/E 先来吐槽一下,一直没机会进div 1, 马力不如当年, 这场题目都不是非常难,div 2 四道题都是水题! 题目大意:给n条直线,保证直线两两不平行,保证三条直线不公点.然后,随机挑三条直线,构成一个三角形,问挑出的三角形的面积的期望. 换句话说,就是算出全部三角形的面积和.再除以三角形的数量.后者是C(n,3), 关键是三角形面积和怎样计算. 下面给我我的思路:O(n^2) 基于三角形的向量表示法, S(A…

题目连接:http://codeforces.com/contest/688/problem/C 题意:给你一些边,问你能否构成一个二分图 题解:二分图:二分图又称作二部图,是图论中的一种特殊模型. 设G=(V,E)是一个无向图,如果顶点V可分割为两个互不相交的子集(A,B),并且图中的每条边(i,j)所关联的两个顶点i和j分别属于这两个不同的顶点集(i in A,j in B),则称图G为一个二分图. 直接上一个DFS就搞定了 #include<cstdio> #include<set…