题目描述 n个学校构成一个有向图,通过m条边连接,一:问至少向图中多少个学校投放软件,可以使得所有学校直接或者间接的通过边(假设存在边(u,v),则向u投放v可以得到,而向v投放u不能通过v直接得到)得到软件(假设每次投放的软件无穷多).二:问至少添加多少条边可以使得只用向一个学校投放软件别的学校都能得到软件 输入格式 The first line contains an integer N: the number of schools in the network (2 <= N <= 10…

Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 16806   Accepted: 6643 Description A number of schools are connected to a computer network. Agreements have been developed among those schools: each school maintains a li…

Network of Schools Time Limit: 1000MS Memory Limit: 10000K Description A number of schools are connected to a computer network. Agreements have been developed among those schools: each school maintains a list of schools to which it distributes softwa…

Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 16803   Accepted: 6641 Description A number of schools are connected to a computer network. Agreements have been developed among those schools: each school maintains a li…

                                                 Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 5354   Accepted: 2106 Description A number of schools are connected to a computer network. Agreements have been developed…

Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 12240   Accepted: 4871 Description A number of schools are connected to a computer network. Agreements have been developed among those schools: each school maintains a li…

                                                            Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 16343   Accepted: 6484 Description A number of schools are connected to a computer network. Agreements have be…

Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 9073   Accepted: 3594 Description A number of schools are connected to a computer network. Agreements have been developed among those schools: each school maintains a lis…

http://poj.org/problem?id=1236 Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 13046   Accepted: 5215 Description A number of schools are connected to a computer network. Agreements have been developed among those scho…

http://poj.org/problem?id=1236 Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 9481   Accepted: 3767 Description A number of schools are connected to a computer network. Agreements have been developed among those schoo…