九度oj 题目1325：Battle Over Cities
http://ac.jobdu.com/problem.php?id=1325 并查集
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1 #include<iostream>
2 using namespace std;
3 struct node
4 {
5 int x,y;
6 };
7 node edge[1000008];//edge
8 int father[1008];
9 int n,m,k;
10 void initSet()
11 {
12 for(int i=0;i<=n;i++) father[i]=i;
13 }
14 int find(int x)
15 {
16 int i=x,temp;
17 while(i!=father[i]) i=father[i];
18 while(x!=i)
19 {
20 temp=father[x];
21 father[x]=i;
22 x=temp;
23 }
24 return i;
25 }
26 int main()
27 {
28 cin>>n>>m>>k;//only one case
29 int i;
30 for(i=0;i<m;i++) cin>>edge[i].x>>edge[i].y;
31 int count,temp,fatherx,fathery;
32 while(k--)
33 {
34 count=0;
35 initSet();
36 cin>>temp;
37 for(i=0;i<m;i++)
38 {
39 fatherx=find(edge[i].x);
40 fathery=find(edge[i].y);
41 if(fatherx!=fathery && edge[i].x!=temp && edge[i].y!=temp)//生成树中排除temp点
42 {
43 father[fatherx]=fathery;
44 count++;//记录出去temp这个点后生成树的边数
45 }
46 }
47 //出去一个点后，的最小生成树如果连通，边数该为（n-1）-1
48 if(n==1) cout<<"0"<<endl;
49 else cout<<n-2-count<<endl;
50 }
51 //system("pause");
52 return 0;
53 }
