luogu_1197 [JSOI2008]星球大战

#include <cstdio>
#include <iostream>
#include <vector>
using namespace std;
const int N=400020;
const int M=200010;
int p[N],n,m,k,a[M],sum,ans[M];
vector<int> G[N];
bool b[N];

int find(int x){return x==p[x]?x:p[x]=find(p[x]);}

int main(){
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)p[i]=i;
    for(int i=1;i<=m;i++){
        int x,y;
        scanf("%d%d",&x,&y);
        G[x].push_back(y); G[y].push_back(x);
    }
    scanf("%d",&k); sum=n-k;
    for(int i=1;i<=k;i++){scanf("%d",&a[i]); b[a[i]]=1;}
    for(int i=1;i<=n;i++){
        if(b[i])continue;
        for(int j=0;j<G[i].size();j++){
            int v=G[i][j];
            if(find(v)!=find(i) && b[v]==0){
                sum--;
                p[find(v)]=find(i);
            }
        }
    }
    for(int i=k;i>=0;i--){
        ans[i]=sum; sum++; b[a[i]]=0;
        for(int j=0;j<G[a[i]].size();j++){
            int v=G[a[i]][j];
            if(find(v)!=find(a[i]) && b[v]==0){
                sum--;
                p[find(v)]=find(a[i]);
            }
        }
    }
    for(int i=0;i<=k;i++)printf("%d\n",ans[i]);
    return 0;
}