luogu P3178 [HAOI2015]树上操作

analysis

一看题，修改点和链查询子树点集的权值和，就是树链剖分了！

code

#include
using namespace std;
#define loop(i,start,end) for(register int i=start;i<=end;++i)
#define anti_loop(i,start,end) for(register int i=start;i>=end;--i)
#define clean(arry,num) memset(arry,num,sizeof(arry))
#define ll long long
#define max(a,b) ((a>b)?a:b)
#define min(a,b) ((a
int n,m,cnt=0;
const int maxn=100000+10;
const int maxm=100000+10;
struct node{
    int e;int nxt;
}edge[maxn<<1];
int head[maxn];
int fa[maxn],dep[maxn],siz[maxn],son[maxn];
int seg[maxn],rev[maxn],top[maxn];
int num[maxn];
ll sum[maxn<<2],lazy[maxn<<2];
template<typename T>void read(T &x){
    x=0;char r=getchar();T neg=1;
    while(r<'0'||r>'9'){if(r=='-')neg=-1;r=getchar();}
    while(r>='0'&&r<='9'){x=(x<<1)+(x<<3)+r-'0';r=getchar();}
    x*=neg;
}
inline void addl(int u,int v){
    edge[cnt].e=v;
    edge[cnt].nxt=head[u];
    head[u]=cnt++;
}
void dfs1(int u,int f){
    fa[u]=f;
    dep[u]=dep[f]+1;
    siz[u]=1;
    for(int i=head[u];i!=-1;i=edge[i].nxt){
        int v=edge[i].e;
        if(v==f)continue;
        dfs1(v,u);
        siz[u]+=siz[v];
        son[u]=((siz[son[u]]<siz[v])?v:son[u]);//siz[0]==0
    }
}
void dfs2(int u,int fa){
    if(son[u]){
        seg[son[u]]=++seg[0];//seg[u]=++seg[0];
        rev[seg[0]]=son[u];//rev[seg[0]]=u;
        top[son[u]]=top[u];
        dfs2(son[u],u);
    }
    for(int i=head[u];i!=-1;i=edge[i].nxt){
        int v=edge[i].e;
        if(!top[v]){
            seg[v]=++seg[0];
            rev[seg[0]]=v;
            top[v]=v;
            dfs2(v,u);
        }
    }
}
inline void pushdown(int l,int r,int rt){
    if(!lazy[rt])return;
    lazy[rt<<1]+=lazy[rt];
    lazy[rt<<1|1]+=lazy[rt];
    sum[rt<<1]+=lazy[rt]*(((r+l)>>1)-l+1);//sum[rt<<1|1]+=lazy[rt]*(((r+l)>>1)-l+1);
    sum[rt<<1|1]+=lazy[rt]*(r-(((l+r)>>1)+1)+1);
    lazy[rt]=0;
}
inline void pushup(int rt){
    sum[rt]=sum[rt<<1]+sum[rt<<1|1];
}
void build(int l,int r,int rt){
    if(l==r){
        sum[rt]=num[rev[l]];
        return;
    }
    int mid=l+((r-l)>>1);
    build(l,mid,rt<<1);
    build(mid+1,r,rt<<1|1);
    pushup(rt);
}
ll query(int l,int r,int nl,int nr,int rt){
    if(l<=nl&&nr<=r){
        return sum[rt];
    }
    pushdown(nl,nr,rt);
    int mid=(nl+((nr-nl)>>1));//int mid=(l+((r-l)>>1));
    ll _sum=0;
    if(mid>=l)_sum+=query(l,r,nl,mid,rt<<1);
    if(mid<r)_sum+=query(l,r,mid+1,nr,rt<<1|1);
    return _sum;
}
void update(int l,int r,int nl,int nr,int rt,ll w){
    if(l<=nl&&nr<=r){
        lazy[rt]+=w;
        sum[rt]+=w*(nr-nl+1);
        return;
    }
    pushdown(nl,nr,rt);
    int mid=nl+((nr-nl)>>1);
    if(mid>=l)update(l,r,nl,mid,rt<<1,w);
    if(mid<r)update(l,r,mid+1,nr,rt<<1|1,w);
    pushup(rt);
}
inline void reply(){
    int op;
    loop(i,1,m){
        read(op);
        if(op==1){
            int x,a;read(x),read(a);
            update(seg[x],seg[x],1,seg[0],1,a);
        }
        else if(op==2){
            int x,a;read(x),read(a);
            update(seg[x],seg[x]+siz[x]-1,1,seg[0],1,a);
        }
        else if(op==3){
            int x;read(x);
            int fx=top[x];
            ll _sum=0;
            while(fx!=1){
                _sum+=query(seg[fx],seg[x],1,seg[0],1);
                x=fa[fx],fx=top[x];
            }
            _sum+=query(seg[1],seg[x],1,seg[0],1);
            printf("%lld\n",_sum);
        }
    }
}
int main(){
    #ifndef ONLINE_JUDGE
    freopen("datain.txt","r",stdin);
    #endif
    clean(son,0),clean(dep,0),clean(fa,0),clean(siz,0);clean(head,-1);clean(top,0);
    read(n),read(m);
    loop(i,1,n)read(num[i]);
    loop(i,1,n-1){
        int vi,ui;
        read(vi),read(ui);
        addl(ui,vi);
        addl(vi,ui);
    }
    dfs1(1,0);
    seg[0]=1;seg[1]=1;rev[1]=1;top[1]=1;
    dfs2(1,0);
    //loop(i,1,n)printf("point:%d dep:%d son:%d siz:%d fa:%d seg:%d rev:%d top:%d\n",i,dep[i],son[i],siz[i],fa[i],seg[i],rev[i],top[i]);
    build(1,seg[0],1);
    reply();
    return 0;
}