Submission #163199

#	Time	Username	Problem	Language	Result	Execution time	Memory
163199		TadijaSebez	전압 (JOI14_voltage)	C++11	100 / 100	156 ms	14072 KiB

voltage

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
const int N=100050;
vector<int> E[N];
int even[N],odd[N],dep[N],all_odd;
bool was[N];
void DFS(int u)
{
	was[u]=1;
	int p=1;
	for(int v:E[u])
	{
		if(!was[v])
		{
			dep[v]=dep[u]+1;
			DFS(v);
		}
		else if(dep[u]>dep[v])
		{
			if(dep[u]==dep[v]+1 && p) p--;
			else
			{
				if((dep[u]-dep[v])%2==0) odd[u]++,odd[v]--,all_odd++;
				else even[u]++,even[v]--;
			}
		}
	}
}
void SubTree(int u)
{
	was[u]=1;
	for(int v:E[u])
	{
		if(!was[v])
		{
			SubTree(v);
			odd[u]+=odd[v];
			even[u]+=even[v];
		}
	}
}
int main()
{
	int n,m;
	scanf("%i %i",&n,&m);
	for(int i=1,u,v;i<=m;i++) scanf("%i %i",&u,&v),E[u].pb(v),E[v].pb(u);
	for(int i=1;i<=n;i++) if(!was[i]) DFS(i);
	for(int i=1;i<=n;i++) was[i]=0;
	for(int i=1;i<=n;i++) if(!was[i]) SubTree(i);
	int ans=0;
	for(int i=1;i<=n;i++) if(dep[i]!=0 && odd[i]==all_odd && even[i]==0) ans++;
	if(all_odd==1) ans++;
	printf("%i\n",ans);
	return 0;
}

Compilation message (stderr)

voltage.cpp: In function 'int main()':
voltage.cpp:46:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%i %i",&n,&m);
  ~~~~~^~~~~~~~~~~~~~~
voltage.cpp:47:59: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1,u,v;i<=m;i++) scanf("%i %i",&u,&v),E[u].pb(v),E[v].pb(u);
                            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 35 / 35
• Subtask 4: 45 / 45