统计块个数写错了调了好久啊，BZOJ1696的弱化版本。
1 #include <iostream> 2 #include <cstring> 3 #include <algorithm> 4 #include <cstdio> 5 #include <map> 6 #define fi first 7 #define se second 8 #define mp make_pair 9 #define pa pair<int,int> 10 using namespace std; 11 inline void Get_Int(int &x) 12 { 13 x=0; char ch=getchar(); int f=1; 14 while (ch<'0' || ch>'9') {if (ch=='-') f=-1; ch=getchar();} 15 while (ch>='0' && ch<='9') {x=x*10+ch-'0'; ch=getchar();} x*=f; 16 } 17 inline void Put_Int(int x) 18 { 19 char ch[20]; int top=0; 20 if (x==0) ch[++top]='0'; 21 while (x) ch[++top]=x%10+'0',x/=10; 22 while (top) putchar(ch[top--]); putchar(' '); 23 } 24 25 const int Maxn=500200; 26 int father[Maxn],head[Maxn],Ans[Maxn],res,u[Maxn],cnt,v[Maxn],n,m,Q,Pos[Maxn]; 27 bool b[Maxn],ret[Maxn]; 28 struct Edge{int to,next;}edge[Maxn<<1]; 29 int getfather(int x) {if (x==father[x]) return x; return father[x]=getfather(father[x]);} 30 inline void Merge(int u,int v) {father[getfather(u)]=getfather(v);} 31 inline void Add(int u,int v) {edge[cnt].to=v;edge[cnt].next=head[u];head[u]=cnt++;} 32 inline void Build() 33 { 34 for (int i=1;i<=n;i++) 35 { 36 if (b[i]) continue; 37 for (int j=head[i];j!=-1;j=edge[j].next) if (!b[edge[j].to]) Merge(i,edge[j].to); 38 } 39 } 40 41 int main() 42 { 43 Get_Int(n),Get_Int(m); 44 for (int i=1;i<=n;i++) father[i]=i; 45 memset(head,-1,sizeof(head)); cnt=0; 46 memset(b,false,sizeof(b)); 47 for (int i=1;i<=m;i++) Get_Int(u[i]),Get_Int(v[i]),Add(u[i]+1,v[i]+1),Add(v[i]+1,u[i]+1); 48 Get_Int(Q); 49 for (int i=1;i<=Q;i++) Get_Int(Pos[i]),Pos[i]++,b[Pos[i]]=true; 50 Build(); 51 memset(ret,false,sizeof(ret)); 52 for (int i=1;i<=n;i++) ret[getfather(i)]=true; 53 int res=0; for (int i=1;i<=n;i++) if (ret[i]) res++;//写成了ret[getfather[i]]了>_< 54 res-=Q; 55 for (int i=Q;i>=1;i--) 56 { 57 Ans[i]=res; 58 b[Pos[i]]=false; 59 for (int j=head[Pos[i]];j!=-1;j=edge[j].next) 60 if (!b[edge[j].to]) 61 if (getfather(Pos[i])!=getfather(edge[j].to)) res--,Merge(Pos[i],edge[j].to); 62 res++; 63 } 64 Ans[0]=res; 65 for (int i=0;i<=Q;i++) Put_Int(Ans[i]); 66 return 0; 67 68 }