The cone size that satisfies the question of hdu3756 by two or three points

/*************************************** * **************** Question: to obtain the minimum volume of a cone, it is required that the cone must cover all given points. Because it is three-dimensional and difficult to process, it is abstracted into a range for consideration; the volume of the cone V = 1/3 * (Pi * r) * h; therefore, the affected volume is h * r, therefore, you can only consider searching. Here, we can use two or three points. Pay attention to sorting. We also need to use Cartesian triangles. Because we can associate h with r, search for h in binary search; **************************************** * ****************/# include <iostream> # include <cstdio> # include <cstring> # include <algorithm> # include <cmath> using namespace std; const int n= 10010; struct point {double x; double y; double z;} p [N]; double dist (const point &) // distance to the Z axis {return sqrt (. x *. x +. y *. y);} double find_r (double h, int t) {double r = 0; for (int I = 0; I <t; I ++) {if (r