Run Away 模拟退火

 1 #include <iostream>
 2 #include <math.h>
 3 #include <stdio.h>
 4 #include <string.h>
 5 #include <time.h>
 6 #include <algorithm>
 7 using namespace std;
 8 #define N 50
 9 #define M 10
10 struct point
11 {
12     double x,y,mina;
13 };
14 point p[1100],s,tri[100];
15 int n;
16 double dist(point a,point b)
17 {
18     return (a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y);
19 }
20 double getmina(point tem)
21 {
22     double mina=1e9,t;
23     for(int i=0; i<n; i++)
24     {
25         t=dist(tem,p[i]);
26         if(t<mina)
27             mina=t;
28     }
29     return mina;
30 }
31 void Simulated_Annealing()
32 {
33     int i,j;
34     for(i=0; i<N; i++)
35     {
36         tri[i].x=((rand()%1000)+1.0)/1000.0*s.x;
37         tri[i].y=((rand()%1000)+1.0)/1000.0*s.y;
38         tri[i].mina=getmina(tri[i]);
39     }
40     double temper=s.x+s.y,dx,dy;
41     point tmp;
42     while(temper>0.001)
43     {
44         for(i=0; i<N; i++)
45         {
46             for(j=0; j<M; j++)
47             {
48                 dx=((rand()%1000)+1.0)/1000.0*temper;
49                 dy=sqrt(temper*temper-dx*dx);
50                 if (rand()&1) dx*=-1;
51                 if (rand()&1) dy*=-1;
52                 tmp.x=tri[i].x+dx;
53                 tmp.y=tri[i].y+dy;
54                 if (tmp.x>=0 && tmp.x<=s.x && tmp.y>=0 && tmp.y<=s.y)
55                 {
56                      tmp.mina=getmina(tmp);
57                     if(tmp.mina>tri[i].mina)
58                     {
59                         tri[i]=tmp;
60                     }
61                 }
62             }
63         }
64         temper*=0.6;
65     }
66     int mini=0;
67     for(i=1;i<N;i++)
68     if(tri[mini].mina<tri[i].mina)
69     mini=i;
70       printf("The safest point is (%.1lf, %.1lf).\n",tri[mini].x,tri[mini].y);
71 }
72 int main()
73 {
74     srand((unsigned int)(time(NULL)));
75     int t,i;
76     scanf("%d",&t);
77     while(t--)
78     {
79         scanf("%lf%lf%d",&s.x,&s.y,&n);
80         for(i=0; i<n; i++)
81         {
82             scanf("%lf%lf",&p[i].x,&p[i].y);
83         }
84         Simulated_Annealing();
85     }
86 }