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