/* poj1873 The Fortified Forest 凸包+枚举 水题 用小树林的木头给小树林围一个围墙 每棵树都有价值 求消耗价值最低的做法,输出被砍伐的树的编号和剩余的木料 若砍伐价值相同,则取砍伐数小的方案. */ #include<stdio.h> #include<math.h> #include <algorithm> #include <vector> using namespace std; const double eps = 1…

LINK 题意:给出点集,每个点有个价值v和长度l,问把其中几个点取掉,用这几个点的长度能把剩下的点围住,要求剩下的点价值和最大,拿掉的点最少且剩余长度最长. 思路:1999WF中的水题.考虑到其点的数量最多只有15个,那么可以使用暴力枚举所有取点情况,二进制压缩状态,预处理出该状态下的价值,同时记录该状态拥有的点,并按价值排序.按价值枚举状态,并对拥有的这些点求凸包,check是否合法,找到一组跳出即可.然而POJ似乎没有SPJ,同样的代码POJ会超时,UVA60ms,可以在常数上优化,不预处…

The Fortified Forest Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 6400   Accepted: 1808 Description Once upon a time, in a faraway land, there lived a king. This king owned a small collection of rare and valuable trees, which had been…

Description Once upon a time, in a faraway land, there lived a king. This king owned a small collection of rare and valuable trees, which had been gathered by his ancestors on their travels. To protect his trees from thieves, the king ordered that a…

题目链接:UVA 811 Description Once upon a time, in a faraway land, there lived a king. This king owned a small collection of rare and valuable trees, which had been gathered by his ancestors on their travels. To protect his trees from thieves, the king or…

n最大15,二进制枚举不会超时.枚举不被砍掉的树,然后求凸包 #include<stdio.h> #include<math.h> #include<algorithm> #include<iostream> #include <cstring> #define eps 1e-8 #define INF 1e9 using namespace std; const int MAXN = 20; struct Point { int x,y; in…

通过这道题发现了原来写凸包的一些不注意之处和一些错误..有些错误很要命.. 这题 N = 15 1 << 15 = 32768 直接枚举完全可行 卡在异常情况判断上很久,只有 顶点数 >= 2,即 n >= 3 时凸包才有意义 顶点数为 1 时,tmp = - 1 要做特殊判断. 总结了一下凸包模板 //template Convex Hull friend bool operator < (const point &p1, const point &p2){…

Problem Description Given two integers n and m, count the number of pairs of integers (a,b) such that 0 < a < b < n and (a^2+b^2 +m)/(ab) is an integer. This problem contains multiple test cases! The first line of a multiple input is an integer N…

转载请注明出处:http://blog.csdn.net/u012860063/article/details/37509207 题目链接:http://codeforces.com/contest/445/problem/C ----------------------------------------------------------------------------------------------------------------------------------------…

题目 链接 给出方程组:$$\displaystyle \left\{\begin{aligned}11x + 13y + 17z = 2471 \\13x + 17y + 11z = 2739\end{aligned}\right.$$已知 $x$,$y$,$z$ 均为正整数,请你计算$x$,$y$,$z$相加之和的最小值 解决方法 由空间几何知,方程组确定的是一条直线,加上正整数约束就是一条线段,求线段上的点$x+y+z$的最小值. 确定其中一个可求出另外两个,枚举其中范围较小的,$1 \l…