p4475 巧克力王国

传送门

分析

我们多维护一个值,代表某个点子树中所有点的权值和

于是如果某个点它的min和max乘a(/b)的值小于范围则直接把整个子树都加进去

估价函数就是这个点的子树中的理论最小值

代码

#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<cctype>
#include<cmath>
#include<cstdlib>
#include<ctime>
#include<queue>
#include<vector>
#include<set>
#include<map>
#include<stack>
using namespace std;
#define int long long
const int inf = 1e9;
inline int ra(){
    int x=0,f=1;char s=getchar();
    while(!isdigit(s)){if(s=='-')f=-1;s=getchar();}
    while(isdigit(s))x=(x<<3)+(x<<1)+(s-'0'),s=getchar();
    return x*f;
}
struct kd {
    int d[2],mx[2],mn[2],le,ri,id,sum,val;
};
kd t[300100],now;
int n,m,root,wh,Ans;
inline bool operator < (kd a,kd b){
    return a.d[wh]<b.d[wh];
}
inline void up(int rt){
    for(int i=0;i<2;++i){
      t[rt].mn[i]=min(t[rt].mn[i],min(t[t[rt].le].mn[i],t[t[rt].ri].mn[i]));
      t[rt].mx[i]=max(t[rt].mx[i],max(t[t[rt].le].mx[i],t[t[rt].ri].mx[i]));
    }
    t[rt].sum=t[t[rt].le].sum+t[t[rt].ri].sum+t[rt].val;
}
inline void build(int &x,int le,int ri,int wwh){
    wh=wwh;
    int mid=(le+ri)>>1;
    x=mid;
    nth_element(t+le,t+x,t+ri+1);
    for(int i=0;i<2;++i)
      t[x].mn[i]=t[x].mx[i]=t[x].d[i];
    if(le<x)build(t[x].le,le,mid-1,wwh^1);
    if(ri>x)build(t[x].ri,mid+1,ri,wwh^1);
    up(x);
}
inline int getd(kd a,kd b){
    if(!a.id)return inf;
    int res=0;
    for(int i=0;i<2;++i)res+=a.d[i]*b.d[i];
    return res;
}
inline int calc(int x){
    if(!x)return inf;
    int res=0;
    for(int i=0;i<2;++i)
      res+=min(t[x].mn[i]*now.d[i],t[x].mx[i]*now.d[i]);
    return res;
}
inline int getmax(int x){
    if(!x)return inf;
    int res=0;
    for(int i=0;i<2;++i)
      res+=max(t[x].mn[i]*now.d[i],t[x].mx[i]*now.d[i]);
    return res;
}
inline void qurey(int x){
    if(!x)return;
    if(getmax(x)<now.val){
      Ans+=t[x].sum;
      return;
    }
    int dl=calc(t[x].le),dr=calc(t[x].ri),d=getd(t[x],now);
    if(d<now.val)Ans+=t[x].val;
    if(dl<now.val)qurey(t[x].le);
    if(dr<now.val)qurey(t[x].ri);
}
signed main(){
    int i,j,k;
    t[0].mn[0]=t[0].mn[1]=inf;
    t[0].mx[0]=t[0].mx[1]=-inf;
    scanf("%lld%lld",&n,&m);
    for(i=1;i<=n;++i){
      t[i].d[0]=ra(),t[i].d[1]=ra(),t[i].val=ra();
      t[i].id=i;
    }
    build(root,1,n,1);
    for(i=1;i<=m;++i){
      Ans=0;
      now.d[0]=ra(),now.d[1]=ra(),now.val=ra();
      qurey(root);
      printf("%lld
",Ans);
    }
    return 0;
}
原文地址:https://www.cnblogs.com/yzxverygood/p/10562729.html