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https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
49 lines
1.0 KiB
C++
49 lines
1.0 KiB
C++
#include <cstdio>
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#include <cstring>
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#include <cmath>
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#include <iostream>
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#include <algorithm>
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using namespace std;
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const double eps=1e-14;
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const int maxn=303;
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int n;
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struct node{
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double x,y,vx,vy;
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}e[maxn*maxn];
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double cross(node a,node b,double t)
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{
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return (a.x+a.vx*t-b.x-b.vx*t)*(a.x+a.vx*t-b.x-b.vx*t)+(a.y+a.vy*t-b.y-b.vy*t)*(a.y+a.vy*t-b.y-b.vy*t);
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}
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double find(double t)
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{
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double ans=0;
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int i,j;
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for(i=0;i<n;i++)
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for(j=i+1;j<n;j++)
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ans=max(ans,cross(e[i],e[j],t));
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return ans;
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}
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int main()
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{
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int T,tt=0;
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scanf("%d",&T);
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while(T--)
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{
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int i,j,k;
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scanf("%d",&n);
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for(i=0;i<n;i++)
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scanf("%lf%lf%lf%lf",&e[i].x,&e[i].y,&e[i].vx,&e[i].vy);
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double l,r,m1,m2;
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l=0,r=1e8;
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for(i=0;i<100;i++)
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{
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m1=l+(r-l)/3;
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m2=r-(r-l)/3;
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if(find(m1)<find(m2)) r=m2;
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else l=m1;
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}
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printf("Case #%d: %.2lf %.2lf\n",++tt,l,sqrt(find(l)));
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}
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return 0;
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}
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