1 #include<cstdio> 2 #include<utility> 3 #include<vector> 4 #include<algorithm> 5 #define w first 6 #define a second.first 7 #define b second.second 8 typedef std::pair<int,std::pair<int,int> > Edge; 9 const int N=100;10 int n;11 std::vector<Edge> e;12 class UnionFindSet {13     private:14         int anc[N];15     public:16         UnionFindSet(int n) {17             for(int i=0;i<n;i++) anc[i]=i;18         }19         int Find(int x) {20             return (x==anc[x])?x:(anc[x]=Find(anc[x]));21         }22         void Union(int x,int y) {23             anc[Find(y)]=Find(x);24         }25 };26 int main() {27     scanf("%d",&n);28     for(int i=0;i<n;i++) {29         for(int j=0;j<n;j++) {30             int c;31             scanf("%d",&c);32             if(i<j) {33                 e.push_back(std::make_pair(c,std::make_pair(i,j)));34             }35         }36     }37     UnionFindSet s(n);38     std::sort(e.begin(),e.end());39     int ans=0;40     for(int i=0;i<(int)e.size();i++) {41         if(s.Find(e[i].a)==s.Find(e[i].b)) continue;42         ans+=e[i].w;43         s.Union(e[i].a,e[i].b);44     }45     printf("%d\n",ans);46     return 0;47 }