Submission #1819828

---

Source Code Expand

#include<bits/stdc++.h>
#define maxn 100100
using namespace std;
struct edge{
	int u,v,w;
	void scan(){scanf("%d%d%d",&u,&v,&w);}
	int operator<(const edge& e)const{return w<e.w;}
}d[maxn];
int n,m,k,c[maxn],f[maxn],sta[maxn],tp;
int find(int x){
	return x==f[x]?x:f[x]=find(f[x]);
}
int main(){
	scanf("%d%d%d",&n,&m,&k);
	for(int i=1;i<=n;++i)scanf("%d",&c[i]);
	for(int i=1;i<=m;++i)d[i].scan();
	for(int i=1;i<=k;++i)f[i]=i;
	for(int i=1;i<=m;++i)if(c[d[i].u]&&c[d[i].v])
		f[find(c[d[i].u])]=find(c[d[i].v]);
	sort(d+1,d+m+1);
	for(int i=1;i<=k;++i)if(find(i)==i)sta[++tp]=i;
	for(int i=1;i<=m;++i){
		int u=d[i].u,v=d[i].v;
		if(!c[v])swap(u,v);
		if(!c[u]&&!c[v]){
			if(tp==1)c[u]=c[v]=sta[tp];
			else c[u]=sta[tp],c[v]=sta[tp-1],f[find(c[u])]=find(c[v]),tp-=1;
		} else if(!c[u]){
			if(tp==1)c[u]=sta[tp];
			else if(sta[tp]==find(c[v]))
				c[u]=sta[tp-1],f[find(sta[tp-1])]=find(sta[tp]),sta[tp-1]=sta[tp],tp--;
			else c[u]=sta[tp],f[find(sta[tp])]=find(c[v]),tp--;
		} else f[find(c[u])]=find(c[v]);
		while(tp>=2&&find(sta[tp-1])==find(sta[tp]))tp--;
	}
	if(tp!=1)return puts("-1"),0;
	for(int i=1;i<=k;++i)f[i]=i;
	long long ans=0;
	for(int i=1;i<=m;++i)if(find(c[d[i].u])!=find(c[d[i].v]))
		f[find(c[d[i].u])]=find(c[d[i].v]),ans+=d[i].w;
	printf("%lld",ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:14:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d",&n,&m,&k);
                          ^
./Main.cpp:15:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=n;++i)scanf("%d",&c[i]);
                                        ^
./Main.cpp: In member function ‘void edge::scan()’:
./Main.cpp:6:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  void scan(){scanf("%d%d%d",&u,&v,&w);}
                                      ^

Judge Result