DFS

struct node ... {
intid;
intw;
node*next;
} ;

struct arr_node ... {
intid;
node*head;
} ;

arr_nodea[N];
int color[N],d[N],f[N],from[N],time;

void Init() ... {
inti;
for(i=0;i<n;i++)...{
color[i]=0;//0:white1:gray2:black
from[i]=-1;
}
}

void DFS() ... {
Init();
inti;
time=0;
for(i=0;i<n;i++)...{
if(color[i]==0)DFS_visit(intid);
}
}

void DFS_visit( int id) ... {
color[id]=1;
d[id]=++time;
node*p=arr_node[id].head;
while(NULL!=p)...{
if(0==color[p->id])...{
DFS_visit(p->id);
from[p->id]=id;
}
p=p->next;
}
color[id]=2;
f[id]=++time;
}
// cost16'