판단 선분 규범 교차
3618 단어 규범.
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<math.h>
const double eps = 1e-8;
struct point
{
double x, y;
};
point a, b, c, d;
inline int dcmp(double d)
{
if(fabs(d) < eps) return 0;
return d > 0 ? 1 : -1;
}
inline double det(double x1, double y1, double x2, double y2)
{
return x1 * y2 - x2 * y1;
}
inline double cross(point a, point b, point c)
{
return det(b.x - a.x, b.y - a.y, c.x - a.x, c.y - a.y);
}
inline int segcross(point a, point b, point c, point d)
{
return ((dcmp(cross(a, c, d)) ^ dcmp(cross(b, c, d))) == -2
&& (dcmp(cross(c, a, b)) ^ dcmp(cross(d, a, b))) == -2);
}
int main()
{
while(scanf("%lf%lf%lf%lf", &a.x, &a.y, &b.x, &b.y) != EOF)
{
scanf("%lf%lf%lf%lf", &c.x, &c.y, &d.x, &d.y);
if(segcross(a, b, c, d))
printf("Yes
");
else
printf("No
");
}
return 0;
}