Highways

 1 #include <iostream>
 2 using namespace std;
 3 #include<string.h>
 4 #include<set>
 5 #include<stdio.h>
 6 #include<math.h>
 7 #include<queue>
 8 #include<map>
 9 #include<algorithm>
10 #include<cstdio>
11 #include<cmath>
12 #include<cstring>
13 #include <cstdio>
14 #include <cstdlib>
15 #include<cstring>
16 int n;
17 int a[510];
18 int find (int x)
19 {
20     if(a[x]==x)
21         return x;
22     return a[x]=find(a[x]);
23 }
24 int balabalanengliang(int x,int y)
25 {
26     int x1=find(x);
27     int y1=find(y);
28     if(x1==y1)
29         return 1;
30     a[y1]=x1;
31     return 0;
32 }
33 struct lll
34 {
35     int x,y,len;
36 }s;
37 struct cmp1{
38     bool operator ()(lll &a,lll &b){
39         return a.len>b.len;//最小值优先
40     }
41 };
42 priority_queue<lll,vector<lll>,cmp1>TM;
43 
44 int main()
45 {
46     int t;
47     cin>>t;
48     while(t--)
49     {
50         cin>>n;
51         memset(a,0,sizeof(a));
52         for(int i=1;i<=n;i++)
53         {
54             for(int j=1;j<=n;j++)
55             {
56                 a[j]=j;
57                 int t;
58                 cin>>t;
59                 if(i==j)
60                     continue;
61                 s.x=i;
62                 s.y=j;
63                 s.len=t;
64                 TM.push(s);
65             }
66         }
67         int temp;
68         while(!TM.empty())
69         {
70             if(balabalanengliang(TM.top().x,TM.top().y))
71             {
72                TM.pop();
73                continue;
74             }
75             temp=TM.top().len;
76             TM.pop();
77         }
78         cout<<temp<<endl;
79     }
80     return 0;
81 }