poj 2253 最短路floyd **

 1 #include<cstdio>
 2 #include<iostream>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<queue>
 7 #include<map>
 8 using namespace std;
 9 #define MOD 1000000007
10 #define pb(a) push_back(a)
11 const int INF=0x3f3f3f3f;
12 const double eps=1e-5;
13 typedef long long ll;
14 #define cl(a) memset(a,0,sizeof(a))
15 #define ts printf("*****\n");
16 const int MAXN=210;
17 int n,m,tt,cnt;
18 struct Node
19 {
20     int x,y;
21     void in()
22     {
23         scanf("%d%d",&x,&y);
24     }
25 }node[MAXN];
26 double dis(Node a,Node b)
27 {
28     return sqrt((double)(a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
29 }
30 double dist[MAXN][MAXN];
31 
32 int main()
33 {
34     int i,j,k;
35     #ifndef ONLINE_JUDGE
36     freopen("1.in","r",stdin);
37     #endif
38     int ca=1;
39     while(scanf("%d",&n)!=EOF)
40     {
41         if(n==0)    break;
42         for(i=0;i<n;i++)
43         {
44             node[i].in();
45         }
46         cl(dist);
47         for(i=0;i<n;i++)
48         {
49             for(j=0;j<n;j++)
50             {
51                 if(i==j)    continue;
52                 else    dist[i][j]=dist[j][i]=dis(node[i],node[j]);
53             }
54         }
55         for(k=0;k<n;k++)
56         {
57             for(i=0;i<n;i++)
58             {
59                 for(j=0;j<n;j++)
60                 {
61                     if(dist[i][j]>max(dist[i][k],dist[k][j]))   dist[i][j]=max(dist[i][k],dist[k][j]);
62                 }
63             }
64         }
65         printf("Scenario #%d\nFrog Distance = %.3lf\n\n",ca++,dist[0][1]);
66     }
67     return 0;
68 }