一道嚇人的水題 HDU 1140

題目意思很嚇人。經過分析之後就變成了一道比大小的題目... 囧~

#include<set>#include<iostream>using namespace std;class Point3D{public:   double x,y,z;   Point3D( double a=0,double b=0,double c=0 ){      x=a; y=b; z=c;  }}A[111],B[111];double dis( Point3D a,Point3D b ){    return (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 N,M; Point3D O(0,0,0); while( scanf("%d %d",&N,&M)!=EOF ) {    if( N==0&&M==0 )       break;    for( int i=0;i<N;i++ )    scanf( "%lf %lf %lf",&A[i].x,&A[i].y,&A[i].z );    for( int i=0;i<M;i++ )    scanf( "%lf %lf %lf",&B[i].x,&B[i].y,&B[i].z );    int ans=0;    for( int j=0;j<M;j++ )    for( int i=0;i<N;i++ )    {   if( dis(A[i],O)>dis(A[i],B[j])+dis(B[j],O) )   {   ans++;   break; }   }   printf( "%d\n",ans );  }  return 0;}