OJ-Problems-Source/HDOJ/1109_autoAC.cpp

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2016-08-13 10:51:15 +08:00
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <string>
#include <algorithm>
#include <set>
#include<map>
#include<ctime>
using namespace std;
const int NUM=20;
const int RAD=1000;
struct point
{
double x,y,val;
point(){}
point(double _x,double _y):x(_x),y(_y){}
}p[10001],May[NUM],e1,e2;
int n;
double X,Y;
double dis(point a,point b)
{
return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
}
double judge(point t)
{
double len;
len=1LL<<45;
for(int i=0;i<n;i++)
len=min(len,dis(t,p[i]));
return len;
}
double Rand(){return rand()%(RAD+1)/(1.0*RAD);}
point Rand_point(point a,point b)
{
double xx=a.x+(b.x-a.x)*Rand();
double yy=a.y+(b.y-a.y)*Rand();
point tmp=point(xx,yy);
tmp.val=judge(tmp);
return tmp;
}
void solve(double D)
{
May[0]=point(0,0);
May[1]=point(X,Y);
May[2]=point(0,Y);
May[3]=point(X,0);
for(int i=4;i<NUM;i++)
May[i]=Rand_point(May[0],May[1]);
while(D>0.01)
{
for(int i=0;i<NUM;i++)
for(int j=0;j<NUM;j++)
{
point tmp=Rand_point(point(max(0.0,May[i].x-D),max(0.0,May[i].y-D)),point(min(X,May[i].x+D),min(Y,May[i].y+D)));
if(tmp.val>May[i].val)
{
May[i]=tmp;
}
}
D*=0.9;
}
point ans;
ans.val=0;
for(int i=0;i<NUM;i++)
if(May[i].val>ans.val)
ans=May[i];
printf("The safest point is (%.1f, %.1f).\n",ans.x,ans.y);
}
int main()
{
srand(time(0));
e2=point(0,0);
int Case;
scanf("%d",&Case);
while(Case--)
{
scanf("%lf%lf%d",&X,&Y,&n);
for(int i=0;i<n;i++)
{
scanf("%lf%lf",&p[i].x,&p[i].y);
}
solve(max(Y,X));
}
}