10分求助QAQ

#include #include #include #define M 200005 using namespace std; int fa[M]; struct edge{ int h,t,w; }a[M]; bool cmp(edge x,edge y){ return x.w<y.w; } int find(int x){ if(fa[x]==x)return x; fa[x]=find(fa[x]); return fa[x]; } int main(){ freopen("000.in","r",stdin); freopen("000.out","w",stdout); int n,m,ans=0; cin>>n>>m; for(int i=0;i<m;i++){ scanf("%d%d%d",&a[i].h,&a[i].t,&a[i].w); } sort(a,a+m,cmp); for(int i=0;i<n;i++)fa[i]=i; int l,r,b=0; for(int i=0;i<m;i++){ l=a[i].h;r=a[i].t; if(find(l)==find(r))continue; else { fa[find(l)]=find(r); ans+=a[i].w; b++; if(b==n-1)break;

	}
	
	
}
printf("%d",b);
fclose(stdin);
fclose(stdout);
return 0;

} /* 4 5 1 2 2 1 3 2 1 4 3 2 3 4 3 4 3 / / 5 18 2 4 276 3 3 435 3 4 608 2 4 860 1 2 318 1 3 547 5 4 419 2 5 98 1 5 460 5 3 399 3 5 240 3 2 733 3 3 903 4 2 909 5 2 206 3 4 810 2 1 115 2 3 419 */