Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 16571   Accepted: 6558 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 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 software (the “receiving schools”). Note that if B is in t…

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 software (the "receiving schools"). Note that if B is in the…

题目链接:http://poj.org/problem?id=1236 Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 19859   Accepted: 7822 Description A number of schools are connected to a computer network. Agreements have been developed among those…

Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 13801   Accepted: 5505 Description A number of schools are connected to a computer network. Agreements have been developed among those schools: each school maintains a li…

题意: 求一个有向图中: (1)要选几个点才能把的点走遍 (2)要添加多少条边使得整个图强联通 分析: 对于问题1, 我们只要求出缩点后的图有多少个入度为0的scc就好, 因为有入度的scc可以从其他地方到达. 对于问题2, 每个入度为0的scc, 都可以补一条边可以变成强连通图, 每个出度为0的scc, 也可以补一条边使其变成强连通图. 所以答案就是max(入度为0scc个数,出度为0scc个数). #include<cstdio> #include<iostream> #inc…

题目链接Network of Schools 参考斌神博客 强连通分量缩点求入度为0的个数和出度为0的分量个数 题目大意:N(2<N<100)各学校之间有单向的网络,每个学校得到一套软件后,可以通过单向网络向周边的学校传输,问题1:初始至少需要向多少个学校发放软件,使得网络内所有的学校最终都能得到软件.2,至少需要添加几条传输线路(边),使任意向一个学校发放软件后,经过若干次传送,网络内所有的学校最终都能得到软件.   也就是: —        给定一个有向图,求:   1) 至少要选几个顶…

poj.org/problem?id=1236 [题意] 给定一个有向图,求: (1)至少要选几个顶点,才能做到从这些顶点出发,可以到达全部顶点 (2)至少要加多少条边,才能使得从任何一个顶点出发,都能到达全部顶点 [思路] (1)强连通分量缩点后形成一个有向无环图,只要选择入度为0的顶点,其他顶点都可以被到达 (2)等价于一个有向无环图加最少加多少条边能够变成一个强连通图,取出度为0的点的个数和入度为0的点的个数的max,因为出度为0的点要加一条出边,入度为0的点要加一条入边 (2)特判特殊情…

Network of Schools Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 27121   Accepted: 10704 Description A number of schools are connected to a computer network. Agreements have been developed among those schools: each school maintains a l…

题目链接 题意:有n个节点的图,现在给出了m个边,问最小加多少边是的图是强连通的 分析:首先找到强连通分量,然后把每一个强连通分量缩成一个点,然后就得到了一个DAG.接下来,设有a个节点(每个节点对应一个强连通分量)的入度为0,b个节点的出度为0,然后取ab最大的就行了 #include <iostream> #include <cstdio> #include <cstring> #include <vector> #include <stack&g…