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[N],v[N<<1],nxt[N<<1],ed;
    int f[N],son[N][2],val[N],tag[N],sum[N],ts[N],td[N],size[N],tmp[N];
    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;
}