想清楚后能发现就要让我们求最小生成树（如果图连通的话，否则就是森林）
//#pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #include<cstring> #include<cstdlib> #include<algorithm> #include<iostream> #include<sstream> #include<cmath> #include<climits> #include<string> #include<map> #include<queue> #include<vector> #include<stack> #include<set> using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair<int,int> pii; #define pb(a) push(a) #define INF 0x1f1f1f1f #define lson idx<<1,l,mid #define rson idx<<1|1,mid+1,r #define PI 3.1415926535898 template<class T> T min(const T& a,const T& b,const T& c) { return min(min(a,b),min(a,c)); } template<class T> T max(const T& a,const T& b,const T& c) { return max(max(a,b),max(a,c)); } void debug() { #ifdef ONLINE_JUDGE #else freopen("in.txt","r",stdin); //freopen("d:\out1.txt","w",stdout); #endif } int getch() { int ch; while((ch=getchar())!=EOF) { if(ch!=' '&&ch!=' ')return ch; } return EOF; } struct Edge { int u,v,w; bool operator < (const Edge &ant) const { return w<ant.w; } }; vector<Edge> edge; int n,m,k; int a[20002]; void InitUnionFind() { for(int i=0;i<n+m;i++) a[i]=i; } int find(int x) { return x==a[x]?x:a[x]=find(a[x]); } void marge(int fa,int fb) { a[fa]=fb; } int MST() { InitUnionFind(); sort(edge.begin(),edge.end()); int res=0; int cnt=0; for(int i=0;i<edge.size();i++) { int a=edge[i].u; int b=edge[i].v; int fa=find(a),fb=find(b); if(fa!=fb) { res+=edge[i].w; if(++cnt==n+m-1)break; marge(fa,fb); } } return res; } int main() { int t; scanf("%d",&t); for(int ca=1;ca<=t;ca++) { edge.clear(); scanf("%d%d%d",&n,&m,&k); for(int i=1;i<=k;i++) { int u,v,w; scanf("%d%d%d",&u,&v,&w); edge.push_back((Edge){u,v+n,-w}); } printf("%d ",(n+m)*10000+MST()); } return 0; }