[BZOJ]4998: 星球联盟

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
#include <vector>
#include <stack>
#include <queue>
#include <cmath>
#include <set>
#include <map>
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define link(x) for(edge *j=h[x];j;j=j->next)
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,r,l) for(int i=r;i>=l;i--)
const int MAXN=3e5+10;
const double eps=1e-8;
#define ll long long
using namespace std;
struct edge{int t,v;edge*next;}e[MAXN<<1],*h[MAXN],*o=e;
void add(int x,int y,int vul){o->t=y;o->v=vul;o->next=h[x];h[x]=o++;}
ll read(){
    ll x=0,f=1;char ch=getchar();
    while(!isdigit(ch)){if(ch==‘-‘)f=-1;ch=getchar();}
    while(isdigit(ch))x=x*10+ch-‘0‘,ch=getchar();
    return x*f;
}

int f[MAXN];
int find1(int x){
    if(x==f[x])return x;
    return f[x]=find1(f[x]);
}
int pre[MAXN],ch[MAXN][2],res[MAXN],sz[MAXN];
bool rt[MAXN];
void newnode(int t){
    pre[t]=ch[t][0]=ch[t][1]=res[t]=0;rt[t]=1;
}


void reverse(int x){
    if(!x)return ;
    swap(ch[x][0],ch[x][1]);
    res[x]^=1;
}

void push(int x){
    if(res[x]){
	reverse(ch[x][0]);
	reverse(ch[x][1]);
	res[x]^=1;
    }
}

void P(int x){
    if(!rt[x])P(find1(pre[x]));
    push(x);
}

void rotate(int x,int kind){
    int y=find1(pre[x]);
    ch[y][!kind]=ch[x][kind];pre[ch[x][kind]]=y;
    if(rt[y])rt[x]=1,rt[y]=0;
    else ch[find1(pre[y])][ch[find1(pre[y])][1]==y]=x;
    pre[x]=find1(pre[y]);ch[x][kind]=y;pre[y]=x;
}

void splay(int x){
    P(x);
    while(!rt[x]){
	if(rt[find1(pre[x])])rotate(x,ch[find1(pre[x])][0]==x);
	else{
	    int y=find1(pre[x]);int kind=ch[find1(pre[y])][0]==y;
	    if(ch[y][kind]==x)rotate(x,!kind),rotate(x,kind);
	    else rotate(y,kind),rotate(x,kind);
	}
    }
}

void access(int x){
    int y=0;
    while(x){
	splay(x);
	if(ch[x][1])pre[ch[x][1]]=x,rt[ch[x][1]]=1,ch[x][1]=0;
	if(y)rt[y]=0;
	ch[x][1]=y;
	y=x;x=find1(pre[x]);
    }
}

void mroot(int x){access(x);splay(x);reverse(x);}
void Link(int x,int y){
    x=find1(x);y=find1(y);
    mroot(x);mroot(y);
    pre[x]=y;
}

bool pd(int u,int v){
    u=find1(u);v=find1(v);
    while(pre[u])u=find1(pre[u]);
    while(pre[v])v=find1(pre[v]);
    return u==v;
}

int st[MAXN],tot;

void dfs(int x){
    if(!x)return ;
    st[++tot]=x;push(x);
    dfs(ch[x][0]);
    dfs(ch[x][1]);
}

void Tarjan(int u,int v){
    u=find1(u);v=find1(v);
    if(u==v)return ;
    mroot(u);access(v);splay(v);
    tot=0;dfs(v);
    inc(i,2,tot){
	int t1=find1(st[i-1]);
	int t2=find1(st[i]);
	if(t1==t2)continue;
	f[t2]=t1;sz[t1]+=sz[t2];
    }
    inc(i,1,tot)ch[st[i]][0]=ch[st[i]][1]=pre[st[i]]=0,rt[st[i]]=1;
}

int main(){
    int n=read();int m=read();int q=read();
    inc(i,1,n)newnode(i),f[i]=i,sz[i]=1;
    int u,v;
    inc(i,1,m){
	u=read();v=read();
	if(!pd(u,v))Link(u,v);
	else Tarjan(u,v);
    }
    inc(i,1,q){
	u=read();v=read();
	if(!pd(u,v))printf("No\n"),Link(u,v);
	else{
	    Tarjan(u,v);
	    int t1=find1(u);
	    printf("%d\n",sz[t1]);
	}
    }
}