【构造】Ural Championship April 30, 2017 Problem K. King’s island

#include<cstdio>
using namespace std;
struct Point{
	int x,y;
	Point(const int &x,const int &y){
		this->x=x;
		this->y=y;
	}
	Point(){}
}p[1005];
int n,e;
int main(){
//	freopen("k.in","r",stdin);
	bool tag=0;
	int x=-8,y=-19;
	scanf("%d",&n);
	if(n==3){
		puts("0 0\n4 3\n-20 21");
		return 0;
	}
	if(n%2==1){
		++n;
		tag=1;
	}
	p[++e]=Point(0,0);
	p[++e]=Point(-12,-16);
	p[++e]=Point(-8,-19);
	p[++e]=Point(4,-3);
	for(int i=1;i<=(n-4)/2;++i){
		if(i%2==1){
			Point a[3];
			a[0]=Point(x+4*4,y-4*3);
			a[1]=Point(a[0].x+3,a[0].y+4);
			a[2]=Point(x+3,y+4);
			for(int j=e;j>=e/2+2;--j){
				p[j+2]=p[j];
			}
			p[e/2+1]=a[0];
			p[e/2+2]=a[1];
			p[e/2+3]=a[2];
			x=a[0].x;
			y=a[0].y;
			e+=2;
		}
		else{
			Point a[3];
			a[2]=Point(x-3,y-4);
			a[1]=Point(a[2].x-4*4,a[2].y+4*3);
			a[0]=Point(a[1].x+3,a[1].y+4);
			for(int j=e;j>=e/2+1;--j){
				p[j+2]=p[j];
			}
			p[e/2]=a[0];
			p[e/2+1]=a[1];
			p[e/2+2]=a[2];
			x=a[2].x;
			y=a[2].y;
			e+=2;
		}
	}
	if(tag){
		p[e-1]=p[e];
		--e;
	}
	for(int i=1;i<=e;++i){
		printf("%d %d\n",p[i].x,p[i].y);
	}
	return 0;
}