POJ 1679

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <algorithm>
 5 
 6 using namespace std;
 7 const int MAXN=105;
 8 const int inf=10000000;
 9 int map[MAXN][MAXN]; int f[MAXN][MAXN];
10 bool exist[MAXN][MAXN],used[MAXN][MAXN];
11 int least[MAXN],pre[MAXN]; bool vis[MAXN]; 
12 int n,m,ans1,ans2;
13 
14 void prim(){
15     memset(f,0,sizeof(f));
16     least[1]=0;
17     for(int i=2;i<=n;i++){
18         least[i]=map[1][i];
19         if(least[i]!=inf)
20         pre[i]=1;
21     }
22     vis[1]=true;
23     for(int i=1;i<=n;i++){
24         int min=inf,p=-1;
25         for(int k=1;k<=n;k++){
26             if(least[k]<min&&!vis[k]){
27                 p=k; min=least[k];
28             }
29         }
30 
31         if(p==-1) return ;
32         ans1+=min;
33         used[pre[p]][p]=used[p][pre[p]]=1;
34         for(int j=1;j<=n;j++){
35         if(vis[j])
36         f[j][p]=max(f[j][pre[p]],map[pre[p]][p]);
37         f[p][j]=f[j][p];
38         }
39         vis[p]=true;
40         for(int k=1;k<=n;k++){
41             if(!vis[k]&&map[p][k]<least[k]){
42                 least[k]=map[p][k];
43                 pre[k]=p;
44             }
45         }
46     }
47 }
48 
49 void secondT(){
50     ans2=inf;
51     for(int i=1;i<=n;i++){
52         for(int j=1;j<=n;j++){
53             if(exist[i][j]&&!used[i][j]&&ans1 + map[i][j] - f[i][j] < ans2)
54             ans2=ans1 + map[i][j] - f[i][j];
55         }
56     }
57 }
58 
59 int main(){
60     int T; 
61     scanf("%d",&T);
62     while(T--){
63         scanf("%d%d",&n,&m);
64         int u,v,d;
65         ans1=ans2=0;
66         memset(exist,-1,sizeof(exist));
67         for(int i=1;i<=n;i++){
68             for(int j=i;j<=n;j++)
69             map[i][j]=map[j][i]=inf;
70         }
71         for(int i=1;i<=m;i++){
72             scanf("%d%d%d",&u,&v,&d);
73             map[u][v]=map[v][u]=d;
74             exist[u][v]=exist[v][u]=1;
75         }
76         memset(pre,-1,sizeof(pre));
77         memset(used,0,sizeof(used));
78         memset(vis,false,sizeof(vis));
79         prim();
80         secondT();
81         if(ans1==ans2)
82         printf("Not Unique!\n");
83         else printf("%d\n",ans1);
84     }
85     return 0;
86 }