Floyd(稠密图，记录路径)

 1 #include<iostream>
 2 #include<algorithm>
 3 #include<cstdio>
 4 #include<cstdlib>
 5 #include<queue>
 6 #include<vector>
 7 #include<cstring>
 8 #include<cmath>
 9 using namespace std;
10 #define N 111
11 int f[N][N],lj[N][N];
12 int n,m;
13 vector<int>q;
14 void init()
15 {
16     memset(f,0,sizeof(0));
17     memset(lj,-1,sizeof(lj));
18 }
19 void floyd()
20 {
21     for(int k=1;k<=n;k++)
22     {
23         for(int i=1;i<=n;i++)
24         {
25             for(int j=1;j<=n;j++)
26             {
27                 if(f[i][j]>f[i][k]+f[k][j])
28                 {
29                     f[i][j]=f[i][k]+f[k][j];
30                     lj[i][j]=k;
31                 }
32             }
33         }
34     }
35 }
36 
37 void dfs(int u,int v)
38 {
39     if(lj[u][v]==-1)return ;
40     dfs(u,lj[u][v]);
41     q.push_back(lj[u][v]);
42     dfs(lj[u][v],v);
43 }
44 void print()
45 {
46     for(int i=1;i<=n;i++)
47     {
48         for(int j=1;j<=n;j++)
49         {
50             if(i==j)continue;
51             printf("%d->%d   =   %d     ",i,j,f[i][j]);
52             q.clear();
53             q.push_back(i);
54             dfs(i,j);
55             q.push_back(j);
56             for(int k=0;k<q.size();k++)printf("%d ",q[k]);
57             printf("\n");
58         }
59     }
60 }
61 int main()
62 {
63     while(scanf("%d%d",&n,&m)!=EOF)
64     {
65         init();
66         for(int i=1;i<=n;i++)
67         {
68             for(int j=1;j<=n;j++)scanf("%d",&f[i][j]);
69         }
70         floyd();
71         print();
72     }
73     return 0;
74 }