留坑，题解之后再补
1 #include<bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 typedef double db; 5 const int N=3e5+10; 6 struct E { 7 int u,v,c; 8 bool operator<(const E& b)const {return c<b.c;} 9 } e[N]; 10 int n,m,a[N],b[N],fa[N]; 11 ll mi[N],mx[N],dp[N]; 12 int fd(int x) {return ~fa[x]?fa[x]=fd(fa[x]):x;} 13 void mg(int x,int y,int c) { 14 int fx=fd(x),fy=fd(y); 15 if(fx==fy)return; 16 fa[fx]=fy; 17 mx[fy]=max((ll)c,max(mx[fx],mx[fy])); 18 mi[fy]=min(mi[fx],mi[fy]); 19 dp[fy]=min(dp[fx]+dp[fy],mi[fy]*mx[fy]); 20 } 21 22 ll kruskal() { 23 ll ret=0; 24 sort(e+1,e+1+m); 25 for(int i=1; i<=n; ++i)fa[i]=-1,mx[i]=a[i],mi[i]=b[i],dp[i]=mx[i]*mi[i]; 26 for(int i=1; i<=m; ++i) { 27 int u=e[i].u,v=e[i].v,c=e[i].c; 28 mg(u,v,c); 29 } 30 for(int i=1; i<=n; ++i)if(!~fa[i])ret+=dp[i]; 31 return ret; 32 } 33 34 int main() { 35 scanf("%d%d",&n,&m); 36 for(int i=1; i<=n; ++i)scanf("%d%d",&a[i],&b[i]); 37 for(int i=1; i<=m; ++i)scanf("%d%d%d",&e[i].u,&e[i].v,&e[i].c); 38 printf("%lld ",kruskal()); 39 return 0; 40 }