usaco07mar专题

C++ P2883 [USACO07MAR]牛交通Cow Traffic

题目描述 随着牛的数量增加,农场的道路的拥挤现象十分严重,特别是在每天晚上的挤奶时间。为了解决这个问题,FJ决定研究这个问题,以能找到导致拥堵现象的瓶颈所在。 牧场共有M条单向道路,每条道路连接着两个不同的交叉路口,为了方便研究,FJ将这些交叉路口编号为1..N,而牛圈位于交叉路口N。任意一条单向道路的方向一定是是从编号低的路口到编号高的路口,因此农场中不会有环型路径。同时,可能存在某两个交叉

POJ 3276 Face The Right Way/洛谷P2882 [USACO07MAR]面对正确的方式 反转

题目描述 Farmer John has arranged his N (1 ≤ N ≤ 5,000) cows in a row and many of them are facing forward, like good cows. Some of them are facing backward, though, and he needs them all to face forward

POJ 3272Cow Traffic /洛谷 P2883 [USACO07MAR]牛交通 双向拓扑排序

题目描述 The bovine population boom down on the farm has caused seriouscongestion on the cow trails leading to the barn. Farmer John has decided toconduct a study to find the bottlenecks in order to reli