给你500个红点和蓝点,让你找多少点红点构成的三角形里没有蓝点. 巧妙啊!我们考虑一个很远位置的点,不妨设这个为O,然后n^2枚举红点,考虑Oij里面蓝点的个数, 然后 对于 ijk这个三角形,我们可以求一 OIJ+OJK+OKI,看是否符合条件. #include <bits/stdc++.h> #define p OvO using namespace std; typedef long long ll; int sign(ll k){ ) ; ) ; ; } struct point {…

给你三根线段判段是否组成了A 条件,两条线段交于端点并且夹角不大于90,第三条线段端点在两条线段上并且划分的大小满足 大:小<4:1 注释很全.(主要是我记不清楚了,,好像过了一个多星期了) #include <bits/stdc++.h> using namespace std; typedef long long ll; typedef long long db; ;}// k3 在 [k1,k2] 内 struct point{ ll x,y; point operator + (…

题目大意 给一个数列,长度不超过 5000,每次可以将其中的一个数加 1 或者减 1,问,最少需要多少次操作,才能使得这个数列单调不降 数列中每个数为 -109-109 中的一个数 做法分析 先这样考虑:如果操作的次数最少,那么最终得到的不降的数列,必然是由原始数列中的数组成的,具体的证明可以使用反证法 知道了上面讲述的性质,这题就好搞了 先将原始数列(设为 A,共 n 个数)中所有的数去重并从小到达排序,保存在另一个数列中(设为 B,共 m 个数) 定义状态:f[i][j] 表示将原始数列中的…

E. Holes Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/13/problem/E Description Little Petya likes to play a lot. Most of all he likes to play a game «Holes». This is a game for one person with following rules: There are…

http://codeforces.com/contest/678/problem/D D. Iterated Linear Function Consider a linear function f(x) = Ax + B. Let's define g(0)(x) = x and g(n)(x) = f(g(n - 1)(x)) for n > 0. For the given integer values A, B, nand x find the value of g(n)(x) mod…

题目链接:http://codeforces.com/problemset/problem/678/D 简单的矩阵快速幂模版题 矩阵是这样的: #include <bits/stdc++.h> using namespace std; typedef __int64 LL; struct data { LL mat[][]; }; LL mod = 1e9 + ; data operator *(data a , data b) { data res; ; i <= ; ++i) { ;…

2016-2017 CT S03E06: Codeforces Trainings Season 3 Episode 6 比赛连接: http://codeforces.com/gym/101124/ 代码地址 http://git.oschina.net/qscqesze/Acm/tree/master/contest/2016-2017%20CT%20S03E06%20Codeforces%20Trainings%20Season%203%20Episode%206?dir=1&filepa…

E. Another Sith Tournament 题目连接: http://www.codeforces.com/contest/678/problem/E Description The rules of Sith Tournament are well known to everyone. n Sith take part in the Tournament. The Tournament starts with the random choice of two Sith who wil…

D. Iterated Linear Function 题目连接: http://www.codeforces.com/contest/678/problem/D Description Consider a linear function f(x) = Ax + B. Let's define g(0)(x) = x and g(n)(x) = f(g(n - 1)(x)) for n > 0. For the given integer values A, B, n and x find t…

C. Joty and Chocolate 题目连接: http://www.codeforces.com/contest/678/problem/C Description Little Joty has got a task to do. She has a line of n tiles indexed from 1 to n. She has to paint them in a strange pattern. An unpainted tile should be painted R…