Kruskal || BZOJ 1601: [Usaco2008 Oct]灌水 || Luogu P1550 [USACO08OCT]打井Watering Hole

题面：P1550 [USACO08OCT]打井Watering Hole

题解：无

代码：

 #include<cstdio>
 #include<cstring>
 #include<iostream>
 #include<algorithm>
 #define ll long long
 using namespace std;
 const int maxn=;
 int N,W[maxn],fa[maxn],num_edge=,edge_head[maxn];
 ll Z,ans;
 struct Edge{int from,to,nx;ll dis;}edge[*maxn*maxn];
 inline void Add_edge(int from,int to,ll dis){
     edge[++num_edge].nx=edge_head[from];
     edge[num_edge].from=from;
     edge[num_edge].to=to;
     edge[num_edge].dis=dis;
     edge_head[from]=num_edge;
     return;
 }
 inline int getf(int n){
     if(fa[n]==n)return n;
     fa[n]=getf(fa[n]);
     return fa[n];
 }
 inline bool cmp(const Edge&a,const Edge&b){return a.dis<b.dis;}
 void Kruskal(){
     int cnt=;
     for(int i=;i<=N;i++)fa[i]=i;
     sort(edge+,edge+num_edge+,cmp);
     for(int i=;i<=num_edge;i++){
         int x=edge[i].from,y=edge[i].to;
         int fx=getf(x),fy=getf(y);
         if(fa[x]!=fa[y]){
             cnt++;
             fa[fx]=fy;
             ans+=edge[i].dis;
         }
     }
     return;
 }
 int main(){
     scanf("%d",&N);
     for(int i=;i<=N;i++)scanf("%d",&W[i]);
     for(int i=;i<=N;i++)Add_edge(,i,W[i]);
     for(int i=;i<=N;i++)
         for(int j=;j<=N;j++){
             scanf("%lld",&Z);
             Add_edge(i,j,Z);
         }
     Kruskal();
     printf("%lld\n",ans);
     return ;
 }

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By:AlenaNuna