ICPC 2018 Malaysia-EXPLORACE

Posted 2021-01-10 scott527407973

题目链接http://exam.upc.edu.cn/problem.php?id=9303&csrf=XwLpb4u93pQU7LfB4tOXe12tvq7Gc70z

最小生成树

直接套板子

 1 #include<bits/stdc++.h>
 2  
 3 using namespace std;
 4 struct rec
 5 {
 6     int x,y,z;
 7 }edge[500010];
 8 int fa[100010],n,m,ans;
 9 bool operator<(rec a,rec b)
10 {
11     return a.z<b.z;
12 }
13 int get(int x)
14 {
15     if(x==fa[x])return x;
16     return fa[x]=get(fa[x]);
17 }
18 int main()
19 {
20     ios::sync_with_stdio(false);
21     cin.tie(0);cout.tie(0);
22     int t;
23     cin>>t;
24     for(int cas=1;cas<=t;cas++){
25         cin>>n>>m;
26         ans=0;
27         for(int i=1;i<=m;i++)
28             cin>>edge[i].x>>edge[i].y>>edge[i].z;
29         sort(edge+1,edge+1+m);
30         for(int i=1;i<=n;i++)   fa[i]=i;
31         for(int i=1;i<=m;i++)
32         {
33             int x=get(edge[i].x);
34             int y=get(edge[i].y);
35             if(x==y)    continue;
36             fa[x]=y;
37             ans+=edge[i].z;
38         }
39         cout<<"Case #"<<cas<<": "<<ans<<" meters"<<endl;
40     }
41     return 0;
42 }