1967384_ac_0ms_56k.c

北大大牛代码 1240道题的原代码 超级权威

# include <stdio.h>
# include <math.h>
//S = 0.5*Sum(p[i].x * p[(i+1)%N].y - p[i].y*p[(i+1)%N].x)

struct node
{
	double x;
	double y;
}p[200];

int main()
{
	int i, n;
	double v, s;

	while(scanf("%d",&n)==1&&n>2)
	{
		s = 0;
		for(i = 0; i < n; i++)
			scanf("%lf%lf",&p[i].x,&p[i].y);
		scanf("%lf",&v);
		for(i = 0; i < n; i++)
			s += p[i].x*p[(i+1)%n].y-p[i].y*p[(i+1)%n].x;
		s /= -2.0;
		printf("BAR LENGTH: %.2lf\n",v/s);
	}
	return 1;
}