三分搜索第一题纪念

三分搜索对于凹凸函数极值非常有效

#include
     
      #include
      
       #define eps 0.00000001struct node{    double x,y,z;};double dist(node a,node b){    return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y)+(a.z-b.z)*(a.z-b.z));}int main(){    int cs,p=1;scanf("%d",&cs);    while(p<=cs)    {        node p1,p2,s,e,d;        scanf("%lf%lf%lf",&d.x,&d.y,&d.z);        scanf("%lf%lf%lf",&s.x,&s.y,&s.z);        scanf("%lf%lf%lf",&e.x,&e.y,&e.z);        while(dist(s,e)>eps)        {            node p1,p2;            p1.x=(s.x+e.x)/2;            p1.y=(s.y+e.y)/2;            p1.z=(s.z+e.z)/2;            double d1=dist(p1,d);            p2.x=(p1.x+e.x)/2;            p2.y=(p1.y+e.y)/2;            p2.z=(p1.z+e.z)/2;            double d2=dist(p2,d);            if(d1