poj 1236——Network of Schools

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
#define maxm 21000
#define maxn 220
int n;
int head[maxn],cnt;
int v[maxm],next[maxm];
int dfn[maxn],low[maxn],step;
int sta[maxn],top;
int ID[maxn],IdNum;
int d_in[maxn],d_out[maxn];
bool vis[maxn];
void add(int a,int b)
{
v[cnt]=b;
next[cnt]=head[a];
head[a]=cnt++;
}
void Init()
{
memset(vis,0,sizeof(vis));
memset(d_in,0,sizeof(d_in));
memset(d_out,0,sizeof(d_out));
memset(head,-1,sizeof(head));
memset(dfn,0,sizeof(dfn));
memset(low,0,sizeof(low));
IdNum=top=step=cnt=0;
}
void tarjan(int u)
{
low[u]=dfn[u]=++step;
sta[++top]=u;
vis[u]=1;
for(int i=head[u];~i;i=next[i])
{
int to=v[i];
if(!dfn[to])
{
tarjan(to);
low[u]=min(low[u],low[to]);
}
else
if(vis[to])
low[u]=min(low[u],dfn[to]);
}
if(low[u]==dfn[u])
{
int x;
IdNum++;
do
{
x=sta[top--];
vis[x]=0;
ID[x]=IdNum;
}while(u!=x);
}
}
void build()
{
for(int i=1;i<=n;i++)
for(int j=head[i];~j;j=next[j])
{
int to=v[j];
if(ID[i]!=ID[to])
{
d_in[ID[to]]++;
d_out[ID[i]]++;
}
}
}
int main()
{
int x;
while(~scanf("%d",&n))
{
Init();
for(int i=1;i<=n;i++)
{
scanf("%d",&x);
while(x)
{
add(i,x);
scanf("%d",&x);
}
}
for(int i=1;i<=n;i++)
if(!dfn[i])
tarjan(i);
build();
int ans1=0;
int ans2=0;
for(int i=1;i<=IdNum;i++)
{
if(d_in[i]==0)
ans1++;
if(d_out[i]==0)
ans2++;
}
if(IdNum!=1)
printf("%d\n%d\n",ans1,max(ans1,ans2));
else
printf("1\n0\n");
}
return 0;
}