刚学模拟退火板子，自己好菜。
1 #include<ctime> 2 #include<cmath> 3 #include<cstdio> 4 #include<cstdlib> 5 #include<algorithm> 6 #define N 10004 7 using namespace std; 8 double n,w[N],now=1000000000000000ll; 9 struct node 10 { 11 double xi; 12 double yi; 13 node(double x,double y):xi(x),yi(y){} 14 node(){} 15 }a[N],ans; 16 double dis(node x,node y) 17 { 18 return sqrt((x.xi-y.xi)*(x.xi-y.xi)+(x.yi-y.yi)*(x.yi-y.yi)); 19 } 20 double work() 21 { 22 int jr=rand()%10000; 23 return (double)jr/10000.0; 24 } 25 double sol(node x) 26 { 27 double ret=0; 28 for(int i=1;i<=n;i++) 29 { 30 ret+=dis(x,a[i])*w[i]; 31 } 32 if(ret<now) 33 { 34 ans=x; 35 now=ret; 36 } 37 return ret; 38 } 39 void sa() 40 { 41 double temp=100000; 42 node JR=ans; 43 while(temp>0.001) 44 { 45 node tmp; 46 tmp.xi=JR.xi+(work()*2-1)*temp; 47 tmp.yi=JR.yi+(work()*2-1)*temp; 48 double delta=sol(JR)-sol(tmp); 49 if(delta>0||exp(delta/temp)>work()) 50 { 51 JR=tmp; 52 } 53 temp*=0.99; 54 } 55 for(int i=1;i<=1000;i++) 56 { 57 node tmp; 58 tmp.xi=ans.xi+(work()*2-1)*temp; 59 tmp.yi=ans.yi+(work()*2-1)*temp; 60 sol(tmp); 61 } 62 } 63 int main() 64 { 65 srand(20030714); 66 scanf("%lf",&n); 67 for(int i=1;i<=n;i++) 68 { 69 scanf("%lf%lf%lf",&a[i].xi,&a[i].yi,&w[i]); 70 ans.xi+=a[i].xi,ans.yi+=a[i].yi; 71 } 72 ans.xi/=n,ans.yi/=n; 73 sa(); 74 printf("%.3lf %.3lf ",ans.xi,ans.yi); 75 return 0; 76 }