判断一个无向图是否是连通图

void def2(g gra,int &vn,int &en,int v)
{
vis[v]=1;
vn++;
arcnode *p;
p=gra.vex[v].first;
while§
{
gn++;
if(vis[p->adjex]0)
{
def2(gra,vn,en,p->adjex);
}
p=p->next;
}
}
if(vngra.n&&(gra.n-1)==en/2)
cout<<“连通图”< else
cout<<“错误”<