P3056 [USACO12NOV]笨牛Clumsy Cows 题目描述 Bessie the cow is trying to type a balanced string of parentheses into her new laptop, but she is sufficiently clumsy (due to her large hooves) that she keeps mis-typing characters. Please help her by computing th…

P3056 [USACO12NOV]笨牛Clumsy Cows 题目描述 Bessie the cow is trying to type a balanced string of parentheses into her new laptop, but she is sufficiently clumsy (due to her large hooves) that she keeps mis-typing characters. Please help her by computing th…

题目传送门 晕牛Dizzy Cows 题目背景 Hzwer 神犇最近又征服了一个国家,然后接下来却也遇见了一个难题. 题目描述 The cows have taken to racing each other around the farm but they get very dizzy when running in circles, and everyone knows that dizzy cows don't produce any milk. Farmer John wants to…

洛谷P1522 [USACO2.4]牛的旅行 Cow Tours 题意: 给出一些牧区的坐标,以及一个用邻接矩阵表示的牧区之间图.如果两个牧区之间有路存在那么这条路的长度就是两个牧区之间的欧几里得距离. 对于一个联通块,称之为一个牧场,也就是说一个牧场内任意一个牧区都可以到达该牧场内的任意的另外一个牧区. 对于一个牧场,它的直径是这个联通块内最短路的最大值. 现在让你在恰当地选择两个牧场,在这两个牧场中各自选一个牧区,在这两个牧区之间建路,要求建路之后所有牧场中最大的直径最小.这里其实如果产生了…

P1821 [USACO07FEB]银牛派对Silver Cow Party 题目描述 One cow from each of N farms (1 ≤ N ≤ 1000) conveniently numbered 1..N is going to attend the big cow party to be held at farm #X (1 ≤ X ≤ N). A total of M (1 ≤ M ≤ 100,000) unidirectional (one-way roads co…

一道\(0/1\)分数规划+负环 POJ原题链接 洛谷原题链接 显然是\(0/1\)分数规划问题. 二分答案,设二分值为\(mid\). 然后对二分进行判断,我们建立新图,没有点权,设当前有向边为\(z=(x,y)\),\(time\)为原边权,\(fun\)为原点权,则将该边权换成\(mid\times time[z]+fun[x]\),然后在上面跑\(SPFA\). 如果有一个环使得\(\sum\{mid\times time[z]+fun[x]\}<0\),则说明\(mid\)小了,而式子…

P2862 [USACO06JAN]把牛Corral the Cows 题目描述 Farmer John wishes to build a corral for his cows. Being finicky beasts, they demand that the corral be square and that the corral contain at least C (1 <= C <= 500) clover fields for afternoon treats. The co…

P2862 [USACO06JAN]把牛Corral the Cows 题目描述 Farmer John wishes to build a corral for his cows. Being finicky beasts, they demand that the corral be square and that the corral contain at least C (1 <= C <= 500) clover fields for afternoon treats. The co…

P2862 [USACO06JAN]把牛Corral the Cows 题目描述 Farmer John wishes to build a corral for his cows. Being finicky beasts, they demand that the corral be square and that the corral contain at least C (1 <= C <= 500) clover fields for afternoon treats. The co…

P2862 [USACO06JAN]把牛Corral the Cows 题目描述 Farmer John wishes to build a corral for his cows. Being finicky beasts, they demand that the corral be square and that the corral contain at least C (1 <= C <= 500) clover fields for afternoon treats. The co…