【树链剖分】[ZJOI2008][HYSBZ/BZOJ1036]树的统计Count

题目链接

树链剖分模板题(有树链剖分求LCA)

代码

#include<cstdio>
#include<algorithm>
#define INF 0x7fffffff
#define MAXN 30000
using namespace std;
int n,m,size[MAXN+10],bl[MAXN+10],length[MAXN+10],fa[MAXN+10],wt[MAXN+10],Q,dep[MAXN+10],pos[MAXN+10];
void Read(int &x){
    char c;
    bool f=0;
    while(c=getchar(),c!=EOF){
        if(c=='-')
            f=1;
        else if(c>='0'&&c<='9'){
            x=c-'0';
            while(c=getchar(),c>='0'&&c<='9')
                x=x*10+c-'0';
            ungetc(c,stdin);
            if(f)
                x=-x;
            return;
        }
    }
}
struct node{
    int v;
    node *next;
}*adj[MAXN+10],edge[MAXN*2+10],*ecnt=edge;
struct Seg_tree{
    int mx,sum;
}tree[MAXN*4+10],*tcnt=tree,*root[MAXN+10];
Seg_tree *New_tree(int len){
    Seg_tree *ret=tcnt;
    tcnt+=4*len;
    return ret;
}
void addedge(int u,int v){
    node *p=++ecnt;
    p->v=v;
    p->next=adj[u];
    adj[u]=p;
}
void dfs1(int u){
    dep[u]=dep[fa[u]]+1;
    size[u]=1;
    for(node *p=adj[u];p;p=p->next){
        if(p->v!=fa[u]){
            fa[p->v]=u;
            dfs1(p->v);
            size[u]+=size[p->v];
        }
    }
}
void insert(Seg_tree *tree,int i,int l,int r,int pos,int wt){
    if(l==r){
        tree[i].mx=tree[i].sum=wt;
        return;
    }
    int mid=(l+r)>>1;
    if(pos<=mid)
        insert(tree,i<<1,l,mid,pos,wt);
    else
        insert(tree,(i<<1)|1,mid+1,r,pos,wt);
    tree[i].mx=max(tree[i<<1].mx,tree[(i<<1)|1].mx);
    tree[i].sum=tree[i<<1].sum+tree[(i<<1)|1].sum;
}
void dfs2(int u,int len){
    int heavy=0;
    for(node *p=adj[u];p;p=p->next)
        if(p->v!=fa[u]&&size[p->v]>size[heavy])
            heavy=p->v;
    if(!heavy){
        int tp=u,i;
        for(i=1;i<len;i++)
            tp=fa[tp];
        root[tp]=New_tree(len);
        length[tp]=len;
        for(i=len;i;i--){
            pos[u]=i;
            bl[u]=tp;
            insert(root[tp],1,1,len,i,wt[u]);
            u=fa[u];
        }
        return;
    }
    dfs2(heavy,len+1);
    for(node *p=adj[u];p;p=p->next)
        if(p->v!=fa[u]&&p->v!=heavy)
            dfs2(p->v,1);
}
int LCA(int x,int y){
    while(bl[x]!=bl[y]){
        if(dep[bl[x]]>=dep[bl[y]])
            x=fa[bl[x]];
        else
            y=fa[bl[y]];
    }
    return dep[x]<dep[y]?x:y;
}
void init(){
    Read(n);
    int i,u,v;
    for(i=1;i<n;i++){
        Read(u),Read(v);
        addedge(u,v);
        addedge(v,u);
    }
    for(i=1;i<=n;i++)
        Read(wt[i]);
    dfs1(1);
    dfs2(1,1);
}
int Get_Max(Seg_tree *tree,int i,int l,int r,int ll,int rr){
    if(l>=ll&&r<=rr)
        return tree[i].mx;
    if(r<ll||l>rr)
        return -INF;
    int mid=(l+r)>>1;
    return max(Get_Max(tree,i<<1,l,mid,ll,rr),Get_Max(tree,(i<<1)|1,mid+1,r,ll,rr));
}
int Get_sum(Seg_tree *tree,int i,int l,int r,int ll,int rr){
    if(l>=ll&&r<=rr)
        return tree[i].sum;
    if(r<ll||l>rr)
        return 0;
    int mid=(l+r)>>1;
    return Get_sum(tree,i<<1,l,mid,ll,rr)+Get_sum(tree,(i<<1)|1,mid+1,r,ll,rr);
}
int Query_Max(int u,int lca){
    int ret=-INF;
    while(bl[u]!=bl[lca]){
        ret=max(Get_Max(root[bl[u]],1,1,length[bl[u]],1,pos[u]),ret);
        u=fa[bl[u]];
    }
    ret=max(Get_Max(root[bl[u]],1,1,length[bl[u]],pos[lca],pos[u]),ret);
    return ret;
}
int Query_sum(int u,int lca){
    int ret=0;
    while(bl[u]!=bl[lca]){
        ret+=Get_sum(root[bl[u]],1,1,length[bl[u]],1,pos[u]);
        u=fa[bl[u]];
    }
    ret+=Get_sum(root[bl[u]],1,1,length[bl[u]],pos[lca],pos[u]);
    return ret;
}
void solve(){
    char s[20];
    int u,v,lca;
    Read(Q);
    while(Q--){
        scanf("%s",s);
        Read(u),Read(v);
        if(s[1]=='S'){
            lca=LCA(u,v);
            printf("%d\n",Query_sum(u,lca)+Query_sum(v,lca)-wt[lca]);
        }
        else if(s[1]=='M'){
            lca=LCA(u,v);
            printf("%d\n",max(Query_Max(u,lca),Query_Max(v,lca)));
        }
        else
            insert(root[bl[u]],1,1,length[bl[u]],pos[u],wt[u]=v);
    }
}
int main()
{
    init();
    solve();
}