BZOJ 2648: SJY摆棋子

Descrption

平面求最近点...(nleqslant 5 imes 10^5)

Solution

KD-Tree.

双倍经验..BZOJ 2716: [Violet 3]天使玩偶

Code

/**************************************************************
    Problem: 2648
    User: BeiYu
    Language: C++
    Result: Accepted
    Time:13864 ms
    Memory:32560 kb
****************************************************************/
 
#include <bits/stdc++.h>
using namespace std;
 
const int N = 1000500;
const int M = 2;
//const int oo = 0x3f3f3f3f; 
const int oo = 0x7fffffff;
 
inline int in(int x=0,char s=getchar(),int v=1) { while(s>'9'||s<'0') v=s=='-'?-1:v,s=getchar();
    while(s>='0'&&s<='9') x=x*10+s-'0',s=getchar();return x*v; }
 
namespace KDTree {
    struct Node {
        int mi[M],mx[M],d[M],ch[2];
        Node() {
            ch[0]=ch[1]=0;
            for(int i=0;i<M;i++) mx[i]=-oo,mi[i]=oo,d[i]=0;
        }
    }p[N];
    int D,cp,ans,rt;
     
    #define lc p[o].ch[0]
    #define rc p[o].ch[1]
    #define mid ((l+r)>>1)
     
    int cmp(const Node &a,const Node &b) { return a.d[D]<b.d[D]; } 
    int dis(const Node &a,const Node &b) {
        int res=0;
        for(int i=0;i<M;i++) res+=abs(a.d[i]-b.d[i]);
        return res;
    }
    int Newnode(Node a) {
        ++cp;p[cp]=Node();
        for(int i=0;i<M;i++) p[cp].d[i]=a.d[i];
        return cp;
    }
    void Update(int o) {
        for(int i=0;i<M;i++) p[o].mi[i]=p[o].mx[i]=p[o].d[i];
        if(lc) for(int i=0;i<M;i++) 
            p[o].mi[i]=min(p[o].mi[i],p[lc].mi[i]),p[o].mx[i]=max(p[o].mx[i],p[lc].mx[i]);
        if(rc) for(int i=0;i<M;i++)
            p[o].mi[i]=min(p[o].mi[i],p[rc].mi[i]),p[o].mx[i]=max(p[o].mx[i],p[rc].mx[i]);
    }
    void Build(int &o,int l,int r,int d) {
        D=d,o=mid,nth_element(p+l,p+o,p+r+1,cmp);
        if(l<o) Build(lc,l,mid-1,(d+1)%M);
        if(r>o) Build(rc,mid+1,r,(d+1)%M);
        Update(o); 
    }
    void insert(int &o,int d,Node a) {
        if(!o) o=Newnode(p[o]),p[o]=a;
        else if(a.d[d]<p[o].d[d]) insert(lc,(d+1)%M,a);
        else insert(rc,(d+1)%M,a);
//      cout<<o<<" "<<lc<<" "<<rc<<" "<<p[o].d[0]<<" "<<p[o].d[1]<<endl;
        Update(o);
    }
    int S(int o,const Node a) {
        int res=0;
        for(int i=0;i<M;i++) res+=max(0,p[o].mi[i]-a.d[i])+max(0,a.d[i]-p[o].mx[i]);
        return res;
    }
    void Query(int o,Node a) {
        if(!o) return;
        ans=min(ans,dis(a,p[o]));
        int ll=lc?S(lc,a):oo,rr=rc?S(rc,a):oo;
        if(ll<rr) {
            if(ll<ans) Query(lc,a);
            if(rr<ans) Query(rc,a);
        } else {
            if(rr<ans) Query(rc,a);
            if(ll<ans) Query(lc,a);
        }
    }
    int Qur(Node a) { return ans=oo,Query(rt,a),ans; }
};
 
using namespace KDTree;
 
int n,q;
 
int main() {
    cp=n=in(),q=in();
    for(int i=1;i<=n;i++) for(int j=0;j<M;j++) p[i].d[j]=in();
    Build(rt=1,1,n,0);
    for(int i=1;i<=q;i++) {
        int opt=in();Node a=Node();
        for(int i=0;i<M;i++) a.d[i]=in();
        if(opt==1) insert(rt,0,a);
        else printf("%d
",Qur(a));
    }return 0;
}