分治,选最左上的点分给根,剩下的极角排序后递归
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
using namespace std;
const int maxn=1520;
int n,X,Y;
struct PO
{
int x,y,d;
bool operator<(const PO &o) const
{
if(x-X>=0&&o.x-X<=0) return 1;
if(x-X<=0&&o.x-X>=0) return 0;
return (y-Y)*(long long)(o.x-X)<(o.y-Y)*(long long)(x-X);
}
}p[maxn];
vector<int> g[maxn];
bool vis[maxn];
int sz[maxn],o[maxn];
int dfs(int u)
{
vis[u]=true;
sz[u]=1;
int ret=0;
for(int i=0,j=g[u].size();i<j;i++)
{
int v=g[u][i];
if(vis[v]) continue;
ret+=dfs(v);
}
sz[u]+=ret;
return sz[u];
}
void calc(int u,int l,int r)
{
vis[u]=true;
int t=l;
for(int i=l+1;i<=r;i++)
{
if((p[i].y<p[t].y)||(p[t].y==p[i].y&&p[i].x<p[t].x))
t=i;
}
if(t!=l) swap(p[l],p[t]);
o[p[l].d]=u;
X=p[l].x; Y=p[l].y;
sort(p+l+1,p+r+1);
int pos=l+1;
for(int i=0,j=g[u].size();i<j;i++)
{
int v=g[u][i];
if(vis[v]) continue;
calc(v,pos,pos+sz[v]-1);
pos+=sz[v];
}
}
int main()
{
scanf("%d",&n);
for(int i=0;i<n-1;i++)
{
int x,y;
scanf("%d%d",&x,&y);
g[x].push_back(y); g[y].push_back(x);
}
for(int i=1;i<=n;i++)
{
int x,y;
scanf("%d%d",&x,&y);
p[i]=(PO){x,y,i};
}
dfs(1);
memset(vis,0,sizeof(vis));
calc(1,1,n);
for(int i=1;i<=n;i++)
printf("%d ",o[i]);
putchar(10);
return 0;
}