BZOJ - 2648 SJY摆棋子 (kd树)

题目链接

kd树+插入操作

不知为啥我的常数纳么大,加了快读才过的┐(゚~゚)┌ 

 1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const int N=1e6+10,inf=0x3f3f3f3f;
 5 struct P {int x[2];} a[N],val[N];
 6 bool cmp1(P a,P b) {return a.x[0]<b.x[0];}
 7 bool cmp2(P a,P b) {return a.x[1]<b.x[1];}
 8 typedef bool (*f)(P,P);
 9 f cmp[2]= {cmp1,cmp2};
10 int ls[N],rs[N],mx[N][2],mi[N][2],n,m,rt,tot;
11 #define mid ((l+r)>>1)
12 int newnode(P p) {
13     int u=++tot;
14     ls[u]=rs[u]=0,val[u]=p;
15     for(int i=0; i<2; ++i)mx[u][i]=mi[u][i]=p.x[i];
16     return u;
17 }
18 void pu(int u) {
19     for(int i=0; i<2; ++i) {
20         mx[u][i]=max(max(mx[ls[u]][i],mx[rs[u]][i]),val[u].x[i]);
21         mi[u][i]=min(min(mi[ls[u]][i],mi[rs[u]][i]),val[u].x[i]);
22     }
23 }
24 int dis(P a,P b) {
25     int ret=0;
26     for(int i=0; i<2; ++i)ret+=abs(a.x[i]-b.x[i]);
27     return ret;
28 }
29 int mind(int u,P p) {
30     if(!u)return inf;
31     int ret=0;
32     for(int i=0; i<2; ++i) {
33         if(p.x[i]>mx[u][i])ret+=p.x[i]-mx[u][i];
34         else if(p.x[i]<mi[u][i])ret+=mi[u][i]-p.x[i];
35     }
36     return ret;
37 }
38 void ins(int& u,P p,int f=0) {
39     if(!u) {u=newnode(p); return;}
40     ins(cmp[f](p,val[u])?ls[u]:rs[u],p,f^1),pu(u);
41 }
42 int qry(int u,P p) {
43     if(!u)return inf;
44     int ret=dis(val[u],p);
45     int dl=mind(ls[u],p),dr=mind(rs[u],p);
46     if(dl<dr) {if(dl<ret)ret=min(ret,qry(ls[u],p)); if(dr<ret)ret=min(ret,qry(rs[u],p));}
47     else {if(dr<ret)ret=min(ret,qry(rs[u],p)); if(dl<ret)ret=min(ret,qry(ls[u],p));}
48     return ret;
49 }
50 void build(int& u,int f=0,int l=1,int r=n) {
51     if(l>r) {u=0; return;}
52     nth_element(a+l,a+mid,a+r+1,cmp[f]);
53     u=newnode(a[mid]);
54     build(ls[u],f^1,l,mid-1),build(rs[u],f^1,mid+1,r),pu(u);
55 }
56 inline void read(int& x) {
57     x=0;
58     bool f=0;
59     char ch=getchar();
60     while(ch<'0'||ch>'9')(ch=='-')&&(f=1),ch=getchar();
61     while(ch>='0'&&ch<='9')x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
62     f&&(x=-x);
63 }
64 int main() {
65     mx[0][0]=mx[0][1]=~inf,mi[0][0]=mi[0][1]=inf;
66     read(n),read(m);
67     for(int i=1; i<=n; ++i)read(a[i].x[0]),read(a[i].x[1]);
68     build(rt);
69     while(m--) {
70         P p;
71         int t;
72         read(t),read(p.x[0]),read(p.x[1]);
73         if(t==1)ins(rt,p);
74         else printf("%d\n",qry(rt,p));
75     }
76     return 0;
77 }

 

posted @ 2019-04-25 15:10  jrltx  阅读(195)  评论(0编辑  收藏  举报