Cod sursa(job #687059)

Utilizator mihaibogdan10Mihai Bogdan mihaibogdan10 Data 22 februarie 2012 01:49:19
Problema Patrate 3 Scor 50
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.01 kb
#include<cstdio>
#include<algorithm>
#include<vector>
#define MOD 95617
using namespace std;

struct per{int x, y;};
vector <per> h[MOD], v;

bool Is(int x, int y){
	int i, ind = abs((x + y) % MOD);
	
	for (i = 0; i < (int) h[ind].size(); i++)
		if (h[ind][i].x == x && h[ind][i].y == y) return true;
	return false;
}

int main(void){
	int n, i, j, N, x, y, x1, x2, y1, y2;
	freopen("patrate3.in", "r", stdin), freopen("patrate3.out", "w", stdout);
	scanf ("%d", &n);
	
	for (i = 0; i < n; i++){
		scanf("%d.%d %d.%d", &x1, &y1, &x2, &y2);
		x = x1 * 10000 + (x1 > 0 ? 1 : -1) * y1;
		y = x2 * 10000 + (x2 > 0 ? 1 : -1) * y2;
		v.push_back((per) {x, y});
		h[abs((x + y) % MOD)].push_back ((per) {x, y});
	}
	
	for (i = 0, N = 0; i < n; i++)
		for (j = 0; j < n; j++)
			if (i != j){
				x1 = v[i].x + v[i].y - v[j].y;
				y1 = v[i].y - v[i].x + v[j].x;
				x2 = v[j].x - v[j].y + v[i].y;
				y2 = v[j].x + v[j].y - v[i].x;
				if 	(Is(x1, y1) && Is(x2, y2)) N++;
			}
	
	printf("%d", N / 4);
}