1 2966最小树并查集模板Build The Electric System
2 #include<stdio.h>
3 #include<algorithm>
4 using namespace std;
5 int pre[501],fee;
6 struct side
7 {
8 int u,v,x;
9 }a[501];
10 bool cmp(const side & a,const side & b)
11 {
12 return a.x<b.x;
13 }
14 int find(int x)
15 {
16 int r=x;
17 while(pre[r]!=r)r=pre[r];
18 int i=x;int j;
19 while(i!=r)
20 {
21 j=pre[i];
22 pre[i]=r;
23 i=j;
24 }
25 return r;
26
27 }
28 void join(int x,int y,int i)
29 {
30 int fx=find(x),fy=find(y);
31 if(fx!=fy)
32 {
33 pre[fx]=fy;
34 if(i!=-1)fee+=a[i].x;
35 }
36 return;
37 }
38 int main()
39 {
40 int cas,n,e,nu,nv,nx;
41 scanf("%d",&cas);
42 while(cas--)
43 {
44 fee=0;
45 scanf("%d%d",&n,&e);
46 for(int i=0;i<n;i++)pre[i]=i;
47 int t=0;
48 for(int i=0;i<e;i++)
49 {
50 scanf("%d%d%d",&nu,&nv,&nx);
51 if(nx==0)join(nu,nv,-1);
52 else {a[t].u=nu;a[t].v=nv;a[t].x=nx;t++;}
53 }
54 sort(a,a+t,cmp);
55 for(int i=0;i<t;i++)
56 {
57 join(a[i].u,a[i].v,i);
58 }
59 printf("%d\n",fee);
60 }
61 }
