c++ strchr函数_strchr函数返回_模拟实现strchr函数(38)

returndmult(pvec(u),pvec(v))/vlen(pvec(u))/vlen(pvec(v));

}

double angle_cos(point3 u1,point3 u2,point3u3,point3 v1,point3 v2,point3 v3){

returndmult(pvec(u1,u2,u3),pvec(v1,v2,v3))/vlen(pvec(u1,u2,u3))/vlen(pvec(v1,v2,v3));

}

double angle_sin(line3 l,plane3 s){

returndmult(subt(l.a,l.b),pvec(s))/vlen(subt(l.a,l.b))/vlen(pvec(s));

}

double angle_sin(point3 l1,point3 l2,point3s1,point3 s2,point3 s3){

returndmult(subt(l1,l2),pvec(s1,s2,s3))/vlen(subt(l1,l2))/vlen(pvec(s1,s2,s3));

}

#define abs(x) ((x)>0?(x):-(x))

struct point{int x,y;};

int gcd(int a,int b){

returnb?gcd(b,a%b):a;

}

int grid_onedge(int n,point* p){

inti,ret=0;

for(i=0;i<n;i)

ret=gcd(abs(p[i].x-p[(i1)%n].x),abs(p[i].y-p[(i1)%n].y));

returnret;

}

int grid_inside(int n,point* p){

inti,ret=0;

for(i=0;i<n;i)

ret=p[(i1)%n].y*(p[i].x-p[(i2)%n].x);

return(abs(ret)-grid_onedge(n,p))/21;

}

#include <math.h>

#define eps 1e-8

struct point{double x,y;};

double xmult(point p1,point p2,point p0){

return(p1.x-p0.x)*(p2.y-p0.y)-(p2.x-p0.x)*(p1.y-p0.y);

}

double distance(point p1,point p2){

returnsqrt((p1.x-p2.x)*(p1.x-p2.x)(p1.y-p2.y)*(p1.y-p2.y));

}

double disptoline(point p,point l1,pointl2){

returnfabs(xmult(p,l1,l2))/distance(l1,l2);

}

point intersection(point u1,point u2,pointv1,point v2){

pointret=u1;

doublet=((u1.x-v1.x)*(v1.y-v2.y)-(u1.y-v1.y)*(v1.x-v2.x))

/((u1.x-u2.x)*(v1.y-v2.y)-(u1.y-u2.y)*(v1.x-v2.x));

ret.x=(u2.x-u1.x)*t;

ret.y=(u2.y-u1.y)*t;

本文来自电脑杂谈，转载请注明本文网址：
http://www.pc-fly.com/a/jisuanjixue/article-34960-38.html