2626: JZPFAR K-D tree

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<queue>
using namespace std;

const int N=100005;
const int INF=1000000007;
int n,D,root;
int ls
,rs
;

struct node
{
int d[2],mn[2],mx[2];
int id;
inline int& operator[](int x)
{
return d[x];
}
}tree
,p;

struct W
{
long long val;
int id;
W () {};
W (long long _,int __) {val=_; id=__;}
};

inline bool operator<(W a,W b)
{
return a.val==b.val?a.id<b.id:a.val>b.val;
}

priority_queue<W> q;

inline int read()
{
int a=0,f=1; char c=getchar();
while (c<'0'||c>'9') {if (c=='-') f=-1; c=getchar();}
while (c>='0'&&c<='9') {a=a*10+c-'0'; c=getchar();}
return a*f;
}

inline bool operator<(node a,node b)
{
return a[D]==b[D]?a[D^1]<b[D^1]:a[D]<b[D];
}

inline void pushup(int k)
{
for (int i=0;i<=1;i++)
{
tree[k].mn[i]=min(tree[k].mn[i],min(tree[ls[k]].mn[i],tree[rs[k]].mn[i]));
tree[k].mx[i]=max(tree[k].mx[i],max(tree[ls[k]].mx[i],tree[rs[k]].mx[i]));
}
}

void build(int &k,int l,int r,int dir)
{
int mid=l+r>>1; k=mid; D=dir;
nth_element(tree+l,tree+mid,tree+r+1);
tree[mid].mn[0]=tree[mid].mx[0]=tree[mid][0];
tree[mid].mn[1]=tree[mid].mx[1]=tree[mid][1];
if (l<mid) build(ls[k],l,mid-1,dir^1);
if (r>mid) build(rs[k],mid+1,r,dir^1);
pushup(k);
}

inline long long sqr(int x)
{
return (long long)x*x;
}

inline long long dis(node a,node b)
{
return (long long)sqr(a[0]-b[0])+(long long)sqr(a[1]-b[1]);
}

inline long long getdis(int x)
{
if (!x) return -2;
long long ans=0;
for (int i=0;i<=1;i++)
ans+=max((long long)sqr(tree[x].mx[i]-p[i]),(long long)sqr(tree[x].mn[i]-p[i]));
return ans;
}

void query(int k)
{
if (!k) return;
long long dl=getdis(ls[k]),dr=getdis(rs[k]),d=dis(p,tree[k]);
if (d>q.top().val||(d==q.top().val&&tree[k].id<q.top().id))
{
q.pop();
q.push(W(d,tree[k].id));
}
if (dl>dr)
{
if (dl>=q.top().val) query(ls[k]);
if (dr>=q.top().val) query(rs[k]);
}
else
{
if (dr>=q.top().val) query(rs[k]);
if (dl>=q.top().val) query(ls[k]);
}
}

int main()
{
n=read();
tree[0].mn[0]=tree[0].mn[1]=INF;
tree[0].mx[0]=tree[0].mx[1]=-INF;
for (int i=1;i<=n;i++)
tree[i][0]=read(),tree[i][1]=read(),tree[i].id=i;
build(root,1,n,1);
int testcase=read();
while (testcase--)
{
while (!q.empty()) q.pop();
p[0]=read(); p[1]=read();
int k=read();
for (int i=1;i<=k;i++) q.push(W(-1,0));
query(root);
printf("%d\n",q.top().id);
}
return 0;
}