/* for vertex i, id of component is in con[i] */
int scc() {
static int dfsres[MAXV];
int i,t,c=0;
memset(vis,0,n);
for(resn=i=0;i<n;i++) if(!vis[i]) dfsvisit(i,-1);
/* transpose graph */
memcpy(dfsres,res,n*sizeof(int));
for(i=0;i<ne;i++) t=from[i],from[i]=to[i],to[i]=t;
countingsort();
memset(vis,0,n);
for(resn=0,i=n-1;i>=0;i--) if(!vis[dfsres[i]]) dfsvisit(dfsres[i],c++);
return c;
}
void dfsvisit(int v,int p) {
int ch=0,i,w;
vis[v]=1;
ud[v]=ulow[v]=++resn;
for(i=gs[v];i<gs[v+1];i++) {
w=to[i];
if(w==p) continue;
if(vis[w]) {
if(ulow[v]>ud[w]) ulow[v]=ud[w];
} else {
dfsvisit(w,v);
if(ulow[v]>ulow[w]) ulow[v]=ulow[w];
if(ulow[w]>=ud[v] && p>-1 && !isartic[v]) isartic[v]=1,ac[acn++]=v;
ch++;
}
}
if(p<0 && ch>1 && !isartic[v]) isartic[v]=1,ac[acn++]=v;
}
void dfsvisit(graph * g, int source, int * p, int * b , int * f , int *s, int *tm) {
printf("%x\n", tm);
*tm = *tm + 1;
b[source] = *tm;
s[source] = 1;
node * ele;
int t;
ele = g->adj[source];
while(ele != NULL) {
t = ele->v;
if(s[t] == 0) {
// discovery edge
p[t] = source;
labelEdge(g, source, t, 'd');
dfsvisit(g, t, p, b, f, s, tm);
}
else if(b[t] < b[source] && s[t] == 1) {
//backward edge
labelEdge(g, source, t, 'b');
}
else if(b[t] > b[source] && s[t] == 2 && f[t] > b[t]) {
// forward edge
labelEdge(g, source, t, 'f');
}
else {
// cross edge
labelEdge(g, source, t, 'c');
}
ele = ele->next;
}
*tm = *tm + 1;
f[source] = *tm;
s[source] = 2;
}
void dfsinit(graph *g, int source) {
int ver = g->v;
int p[ver];
int b[ver];
int f[ver];
int s[ver];
int i=0, t, l;
node * ele;
for(i=0;i<ver;i++) {
p[i] = -1;
b[i] = -1;
f[i] = -1;
s[i] = 0;
}
int q = 0;
int *tm;
tm = &q;
printf("%x", tm);
p[source] = -1;
for(i=0;i<ver;i++) {
if(s[i] == 0)
dfsvisit(g, i, p, b, f, s, tm);
}
for(i=0;i<ver;i++) {
printf("%d\t%d\t%d\t%d\n", p[i], b[i], f[i], s[i]);
}
}
void articulation(int root) {
resn=acn=0;
memset(vis,0,n);
memset(isartic,0,n);
dfsvisit(0,-1);
}
