1 void combine(int x,int y)//rank为当前结点在树上的深度
2 {
3     int t1,t2;
4     t1=find(x),t2=find(y);
5     if(rank[t1]<rank[y])swap(t1,t2);
6     father[t2]=t1;
7     if(rank[t1]==rank[t2])++rank[t1];
8 }