1246.c

平时acm训练时ac的源代码

#include <stdio.h>

main()
{
	long n,i;
	long double x0,y0,x1,y1,a,b,s=0;
	scanf("%ld",&n);
	scanf("%lf %lf",&x0,&y0);
	a=x0;
	b=y0;
	for(i=1;i<n;i++)
	{
		scanf("%lf %lf",&x1,&y1);
		s+=x0*y1-y0*x1;
		x0=x1;
		y0=y1;
	}
	x1=a;
	y1=b;
	s+=x0*y1-y0*x1;
	if(s>0)
		printf("ccw");
	else
		printf("cw");
}