【BZOJ 2850】巧克力王国

　　复习了下KDtree，贴一下新板子233。

 1 #include "bits/stdc++.h"
 2 
 3 using namespace std;
 4 
 5 inline int read(){
 6     int s=0,k=1;char ch=getchar ();
 7     while (ch<'0'|ch>'9') ch=='-'?k=-1:0,ch=getchar();
 8     while (ch>47&ch<='9') s=s*10+(ch^48),ch=getchar();
 9     return s*k;
10 }
11 
12 const int N=5e4+10;
13 
14 typedef long long ll;
15 
16 int Kd;
17 
18 ll A,B,C,ans;
19 
20 #define sum(x)    (x?x->sum:0)
21 
22 struct Point{
23     int d[2],mx[2],mn[2],val;
24     Point *lc,*rc;
25     ll sum;
26     int& operator [](int k){
27         return d[k];
28     }
29     friend bool operator <(Point a,Point b){
30         return a[Kd]<b[Kd];
31     }
32     inline void update(){
33         for (int i=0;i<2;++i)    {
34             mx[i]=mn[i]=d[i];
35             if(lc) mx[i]=max(mx[i],lc->mx[i]),mn[i]=min(mn[i],lc->mn[i]);
36             if(rc) mx[i]=max(mx[i],rc->mx[i]),mn[i]=min(mn[i],rc->mn[i]);
37         }        
38         sum=val+sum(lc)+sum(rc);
39     }
40 }cho[N];
41 
42 #define check(x,y) (A*x+B*y<C)
43 
44 inline int calc(Point x){
45     int ret=0;
46     ret=check(x.mn[0],x.mn[1])+check(x.mx[0],x.mx[1])
47        +check(x.mn[0],x.mx[1])+check(x.mx[0],x.mn[1]);
48     return ret;
49 }
50 
51 struct KdTree{
52     inline Point* build(int l,int r,int now){
53         Kd=now;int mid=l+r>>1;
54         nth_element(cho+l,cho+mid,cho+r+1);
55         Point *t=&cho[mid];
56         if(l^mid)    t->lc=build(l,mid-1,now^1);
57         if(r^mid)    t->rc=build(mid+1,r,now^1);
58         t->update();
59         return t;
60     }
61     inline void query(Point *t){
62         if (check(t->d[0],t->d[1]))    ans+=t->val;
63         int tl=0,tr=0;
64         if(t->lc)    tl=calc(*(t->lc));
65         if(t->rc)    tr=calc(*(t->rc));
66         if(tl&4)    ans+=t->lc->sum;
67         else    if(tl)    query(t->lc);
68         if(tr&4)    ans+=t->rc->sum;
69         else    if(tr)    query(t->rc);
70     }
71 
72 }kd;
73 
74 int n,m;
75 
76 int main(){
77     n=read(),m=read();
78     register int i,j;
79     for (i=1;i<=n;++i)
80         cho[i][0]=read(),cho[i][1]=read(),
81         cho[i].val=read();
82     Point *root=kd.build(1,n,0);
83     while (m--){
84         A=read(),B=read(),C=read();
85         ans=0;
86         kd.query(root);
87         printf("%lld\n",ans);
88     }
89 }

 

posted @ 2018-01-28 08:34  Troywar  阅读(264)  评论(0)  编辑  收藏  举报