BZOJ 2888 资源运输（启发式合并LCT）

#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;
const int N=40010;
namespace Heuristic_LCT{
int ans,g
,v[N<<1],nxt[N<<1],ed;
int f
,son
[2],val
,tag
,sum
,ts
,td
,size
,tmp
;
bool isroot(int x){return !f[x]||son[f[x]][0]!=x&&son[f[x]][1]!=x;}
void add1(int x,int p){if(!x)return;val[x]+=p;tag[x]+=p;}
void add2(int x,int s,int d){if(!x)return;sum[x]+=s+size[son[x][1]]*d;ts[x]+=s;td[x]+=d;}
void pb(int x){
if(tag[x]){
add1(son[x][0],tag[x]);
add1(son[x][1],tag[x]);
tag[x]=0;
}
if(td[x]){
add2(son[x][0],ts[x]+(size[son[x][1]]+1)*td[x],td[x]);
add2(son[x][1],ts[x],td[x]);
ts[x]=td[x]=0;
}
}
void up(int x){size[x]=size[son[x][0]]+size[son[x][1]]+1;}
void rotate(int x){
int y=f[x],w=son[y][1]==x;
son[y][w]=son[x][w^1];
if(son[x][w^1])f[son[x][w^1]]=y;
if(f[y]){
int z=f[y];
if(son[z][0]==y)son[z][0]=x;else if(son[z][1]==y)son[z][1]=x;
}f[x]=f[y];f[y]=x;son[x][w^1]=y;up(y);
}
void splay(int x){
int s=1,i=x,y;tmp[1]=i;
while(!isroot(i))tmp[++s]=i=f[i];
while(s)pb(tmp[s--]);
while(!isroot(x)){
y=f[x];
if(!isroot(y)){if((son[f[y]][0]==y)^(son[y][0]==x))rotate(x);else rotate(y);}
rotate(x);
}up(x);
}
void access(int x){for(int y=0;x;y=x,x=f[x])splay(x),son[x][1]=y,up(x);}
int root(int x){access(x);splay(x);while(son[x][0])x=son[x][0];return x;}
void addleaf(int x,int y){
f[y]=x,son[y][0]=son[y][1]=val[y]=tag[y]=sum[y]=ts[y]=td[y]=0,size[y]=1;
x=root(x),access(y),splay(x),add1(x,1),add2(x,0,1);
for(y=son[x][1];son[y][0];y=son[y][0]);splay(y);
int vx=val[x],vy=val[y];
if(vy*2>vx){
val[y]=vx,val[x]-=vy;
sum[x]-=sum[y]+vy,sum[y]+=sum[x]+vx-vy;
access(y),splay(x),son[x][0]=y,son[x][1]=0;
}
}
void dfs(int x,int y){
addleaf(y,x);
for(int i=g[x];i;i=nxt[i])if(v[i]!=y)dfs(v[i],x);
}
void addedge(int x,int y){v[++ed]=y;nxt[ed]=g[x];g[x]=ed;}
void link(int x,int y){
int X=root(x),Y=root(y);
ans-=sum[X]+sum[Y];
if(val[X]<val[Y])swap(x,y);
dfs(y,x),addedge(x,y),addedge(y,x);
ans+=sum[root(x)];
}
void Initialize(){
ans=0;
memset(f,0,sizeof(f));
memset(son,0,sizeof(son));
memset(ts,0,sizeof(ts));
memset(td,0,sizeof(td));
memset(tag,0,sizeof(tag));
}
}
int n,m,x,y;
char op[5];
int main(){
using namespace Heuristic_LCT;
Initialize();
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++)val[i]=size[i]=1;
while(m--){
scanf("%s",op);
if(op[0]=='A')scanf("%d%d",&x,&y),link(x,y);
if(op[0]=='Q')printf("%d\n",ans);
}return 0;
}