1 #include<iostream>
2 #define MAXN 505
3 #define inf 1000000000
4 using namespace std;
5 typedef int elem_t;
6 int _m[MAXN][MAXN];
7 int pre[MAXN];
8 elem_t prim(int n,elem_t mat[][MAXN],int* pre);
9 int main()
10 {
11 //freopen("acm.acm","r",stdin);
12 int num;
13 int i;
14 int j;
15 int min = inf;
16 int time;
17 scanf("%d",&time);
18 while(time --)
19 {
20 scanf("%d",&num);
21 min = 0;
22 for(i = 0; i < num; ++ i)
23 {
24 for(j = 0; j < num; ++ j)
25 _m[i][j] = inf;
26 }
27 for(i = 0; i < num; ++ i)
28 {
29 for(j = 0; j < num; ++ j)
30 {
31 scanf("%d",&_m[i][j]);
32 }
33 }
34 prim(num,_m,pre);
35 for(i = num-1; i >= 0; -- i)
36 {
37 j = i;
38 while(pre[j] != -1)
39 {
40 if(_m[pre[j]][j] > min)
41 min = _m[pre[j]][j];
42 j = pre[j];
43 }
44 }
45 cout<<min<<endl;
46 }
47 }
48
49
50
51 ////////////////////////////////////////////////
52
53 elem_t prim(int n,elem_t mat[][MAXN],int* pre){
54 elem_t min[MAXN],ret=0;
55 int v[MAXN],i,j,k;
56 for (i=0;i<n;i++)
57 min[i]=inf,v[i]=0,pre[i]=-1;
58 for (min[j=0]=0;j<n;j++){
59 for (k=-1,i=0;i<n;i++)
60 if (!v[i]&&(k==-1||min[i]<min[k]))
61 k=i;
62 for (v[k]=1,ret+=min[k],i=0;i<n;i++)
63 if (!v[i]&&mat[k][i]<min[i])
64 min[i]=mat[pre[i]=k][i];
65 }
66 return ret;
67 }
