2240.cpp

这是哈尔滨工业大学acmOJ的源代码

/*  This Code is Submitted by wywcgs for Problem 2240 on 2006-05-22 at 19:26:06 */ 
#include <cstdio>

double wp, hp;

bool draw(double, double, double, double, double, double, bool);

int main()
{
	double w, h;
	int n, i, t;

	for(t = 1; scanf("%lf %lf", &w, &h) != EOF && w > 1e-6; t++) {
		scanf("%lf %lf %d", &wp, &hp, &n);
		printf("Case %d:\n", t);
		for(i = 0; i < n; i++) {
			double x, y; scanf("%lf %lf", &x, &y);
			printf("%s\n", draw(0, w, 0, h, x, y, true) ? "black" : "white");
		}
	}
	
	return 0;
}

bool draw(double lx, double rx, double ly, double ry, double tx, double ty, bool blk)
{
	double wl = (rx-lx)*wp+lx, hl = (ry-ly)*hp+ly;
	int wo = (tx > wl), ho = (ty > hl), o = wo*2+ho;
	if(o == 1 || o == 2) return blk;
	else if(o == 0) return draw(lx, wl, ly, hl, tx, ty, !blk);
	else return draw(wl, rx, hl, ry, tx, ty, !blk);
}