这个数据大小，，，额，边是200000条无向边
by violinwang @ 2018-04-10 23:16:19
推荐代码：
```cpp
#include <bits/stdc++.h>
#define M 200000+3
#define N 5100
using namespace std;
struct node{int u,v,w;}e[M];
int fa[N],m,n;
int k=0;
bool vis[M];
void ad (int u,int v,int w){
k++;e[k].u=u;e[k].v=v;e[k].w=w;
}
bool cmp(node aa,node bb){return aa.w<bb.w;}
void cs(){
for (int i=1;i<=n;++i)
fa[i]=i;
}
int fnd(int x){
if (fa[x]==x) return x;
return fa[x]=fnd(fa[x]);
}
void un(int x,int y){
int fx=fnd(x),fy=fnd(y);
if (fx!=fy) fa[fx]=fy;
}
int main (){
scanf ("%d%d",&n,&m);
int u,v,w;
for (int i=1;i<=m;++i){
scanf ("%d%d%d",&u,&v,&w);
ad(u,v,w);
}
sort(e+1,e+m+1,cmp);
int mst=0,bn=0;
cs();
for (int i=1;i<=m;++i){
// printf("%d",i);
if (fnd(e[i].u)!=fnd(e[i].v)){
mst+=e[i].w;bn++;
un(e[i].u,e[i].v);
if(bn==n-1) break;
}
}
if (bn!=n-1) puts("orz");
else printf("%d",mst);
return 0;
}
```
看不懂的话可以问
by violinwang @ 2018-04-10 23:24:18
用前向星
by violinwang @ 2018-04-10 23:25:31
@[百里雨晴](/space/show?uid=65458) 数组开小了。
这像是 P1546 的代码？
by Anguei @ 2018-04-11 04:36:23
@[violinwang](/space/show?uid=76204) 谢谢
by 百里雨晴 @ 2018-04-11 21:27:31
@[yyfcpp](/space/show?uid=53062) 谢谢，您的大名早有耳闻
by 百里雨晴 @ 2018-04-11 21:29:41
@[violinwang](/space/show?uid=76204) 呵呵，没学过#define
by 百里雨晴 @ 2018-04-11 21:32:34