[c]hdoj 1174 高数题

http://acm.hdu.edu.cn/showproblem.php?pid=1174

题目标题：爆头

题目大意：给你一堆数据，判断能不能爆头

其实就是个高数的题，还用到了叉乘，这个要是没学过的高数的不得哭了

#include<iostream>#include<stdio.h>#include<math.h>using namespace std;double chacheng(double x1,double y1,double z1,double x2,double y2,double z2){double x=y1*z2-z1*y2;    double y=z1*x2-x1*z2;    double z=x1*y2-y1*x2;    return sqrt(x*x+y*y+z*z);}int main(){double h1,r1,x1,y1,z1;double h2,r2,x2,y2,z2,x3,y3,z3;int n;cin>>n;for(int i=0;i<n;i++){cin>>h1>>r1>>x1>>y1>>z1;cin>>h2>>r2>>x2>>y2>>z2>>x3>>y3>>z3;double re=chacheng(x3,y3,z3,x1-x2,y1-y2,z1+h1-r1-(h2*0.9+z2-r2));         re/=sqrt(x3*x3+y3*y3+z3*z3);        if(re-r1<0.0000001) printf("YES\n");        else printf("NO\n");}return 0;}