P3366 【模板】最小生成树

https://www.luogu.org/problemnew/show/P3366

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
#include <stack>
#include <cmath>
using namespace std;

const int MAXN=5005,MAXM=400005;
int n,m,fa[MAXN],cnt,num,ans;
struct cyq{
	int u,v,w;
}a[MAXM];

int get(){
    char cc=getchar();
    int res=0;
    while (cc<'0'||cc>'9') cc=getchar();
    while (cc>='0'&&cc<='9'){
		res=(res<<3)+(res<<1)+cc-'0';
		cc=getchar();
	}
    return res;
}

bool cmp(cyq aa,cyq bb){
	return aa.w<bb.w;
}

int find(int x){
	if(x==fa[x]) return x;
	return fa[x]=find(fa[x]);
}

int main(){
	int x,y,w;n=get();m=get();
	for(int i=1;i<=n;i++) fa[i]=i;
	for(int i=1;i<=m;i++){
		x=get();y=get();w=get();
		a[++cnt].u=x;a[cnt].v=y;a[cnt].w=w;
	}
	sort(a+1,a+1+cnt,cmp);num=1;
	for(int i=1;i<n;i++){
		while(find(a[num].u)==find(a[num].v) && num<=m) ++num;
		fa[find(a[num].u)]=a[num].v;ans+=a[num].w;
	}
	if(num==m+1) printf("orz\n");
	else printf("%d\n",ans);
	return 0;
}