66 lines
1.7 KiB
C++
66 lines
1.7 KiB
C++
#include <cstdio>
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#include <cmath>
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#include <time.h>
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#include <cstdlib>
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using namespace std;
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const double pi=acos(-1.0);
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const int maxn=1005;
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double x[maxn], y[maxn];
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int n;
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double dis2 (double x1,double y1 ,double x2,double y2)
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{
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double tmp1=x1-x2,tmp2=y1-y2;
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tmp1*=tmp1;
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tmp2*=tmp2;
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return tmp1+tmp2;
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}
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double test(double xx, double yy)
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{
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double max = 0,tmp;
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for (int i=0;i<n;i++)
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if(max<(tmp=dis2(xx,yy,x[i],y[i])))max=tmp;
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return max;
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}
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int main()
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{
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double xx,yy;
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double delta,theta;
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double X,Y;
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double retx,rety,ans;
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while (~scanf("%lf%lf%d",&X,&Y,&n))
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{
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for (int i=0 ; i<n ; i++)
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scanf("%lf%lf",x+i,y+i);
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double ans=1000000000.0;
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for (int i=0 ; i<10 ; ++i)
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{
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xx=((double)(rand()%1001)/1000.0)*X;
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yy=((double)(rand()%1001)/1000.0)*Y;
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double dis=test(xx,yy);
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for (delta=X ; delta>0.001 ; delta*=0.9)
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{
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for (theta=0 ; theta<=2*pi ; theta+=(pi/25.0))
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{
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double tx=xx+delta*cos(theta);
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double ty=yy+delta*sin(theta);
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double tdis=test(tx,ty);
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if(tdis<dis)
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{
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xx=tx;
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yy=ty;
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dis=tdis;
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}
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}
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}
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if(dis<ans)
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{
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retx=xx;
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rety=yy;
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ans=dis;
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}
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}
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printf("(%.1lf,%.1lf).\n%.1lf\n",retx,rety,sqrt(ans));
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}
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return 0;
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}
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