[LnOI2019]长脖子鹿省选模拟赛 东京夏日相会

第一眼：凸包？不会。。。

第二眼：模拟退火可做。。。

于是开始打

20min后 WOC 20pts+TLE

疯狂调参....

20min后 WOC 40pts+TLE+WA

疯狂调参...

10min后 WOC 还是40...

然后把某人的生日换成了长者的生日

我去80分...NB

正解到时候如果我会的话会发布...但我不会的话可能就不会发布了

 1 #pragma GCC optimize(2)
 2 #pragma GCC optimize(3)
 3 #pragma GCC optimize("inline")
 4 #pragma GCC optimize("Ofast")
 5 #include<cstdio>
 6 #include<iostream>
 7 #include<cstring>
 8 #include<cmath>
 9 #include<algorithm>
10 #include<cstdlib> 
11 #include<ctime>
12 #define max(a,b) ((a>b)?(a):(b))
13 using namespace std;
14 inline int read(){
15     int ans=0,f=1; char chr=getchar();
16     while(!isdigit(chr)){if(chr=='-') f=-1;chr=getchar();}
17     while(isdigit(chr)) {ans=(ans<<3)+(ans<<1)+chr-48;chr=getchar();}
18     return ans*f;
19 }
20 int n;
21 double x[50005],y[50005],z[50005],ansx,ansy;
22 double dis(double x,double y,double a,double b){return sqrt((x-a)*(x-a)+(y-b)*(y-b));}
23 double get(double q,double p){
24     register double ans=0;
25     for(register int i=1;i<=n;++i)
26         ans=max(dis(x[i],y[i],q,p)+z[i],ans) ;
27     return ans;
28 }
29 const double delta=0.9956;
30 double ans=1e20;
31 void Fire(){
32     register double fx=ansx,fy=ansy;
33     register double t=1217.0;
34     while(t>1e-14){
35         register double tx=fx+(rand()*2-RAND_MAX)*t;
36         register double ty=fy+(rand()*2-RAND_MAX)*t;
37         register double tans=get(tx,ty);
38         register double DE=-ans+tans;
39         if(DE<0){
40             fx=tx;
41             fy=ty;
42             ansx=tx;
43             ansy=ty;
44             ans=tans;
45         }else if(exp(-DE/t)*RAND_MAX>rand())
46             fx=tx,fy=ty;
47         t*=delta;
48     }
49 }
50 int main(){
51     srand(19260817);
52     n=read();
53     for(register int i=1;i<=n;++i)
54         scanf("%lf%lf%lf",&x[i],&y[i],&z[i]),ansx+=x[i],ansy+=y[i];
55     ansx/=1.0*n;
56     ansy/=1.0*n;
57     Fire();Fire();Fire();Fire();
58     printf("%.2lf %.2lf %.2lf",ansx,ansy,ans);
59     return 0;
60 }