Submission #128517

#	Time	Username	Problem	Language	Result	Execution time	Memory
128517		faustaadp	Shymbulak (IZhO14_shymbulak)	C++17	0 / 100	1550 ms	12068 KiB

shymbulak

#include<bits/stdc++.h>
typedef long long ll;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
ll n,i,ta,tb,p[101010],b[101010],CS,ma,jum,has,j;
vector<ll> v[101010],cyc,isi[101010];
pair<ll,ll> A[101010];
void dfs(ll aa)
{
	b[aa]=1;
	ll ii;
	for(ii=0;ii<v[aa].size();ii++)
	{
		if(v[aa][ii]==p[aa]||b[v[aa][ii]]==2)continue;
		if(b[v[aa][ii]])
		{
			ll tem=aa;
			cyc.pb(tem);
			while(tem!=v[aa][ii])
			{
				tem=p[tem];
				cyc.pb(tem);
			}
		}
		else
		{
			p[v[aa][ii]]=aa;
			dfs(v[aa][ii]);
		}
	}
	b[aa]=2;
}
void dfs1(ll aa,ll bb,ll cc)
{
	isi[i].pb(aa);
	if(ma<cc)
	{
		ma=max(ma,cc);
		jum=0;
	}
	if(ma==cc)
		jum++;
	ll ii;
	for(ii=0;ii<v[aa].size();ii++)
	{
		if(b[v[aa][ii]])continue;
		if(v[aa][ii]==bb)continue;
		dfs1(v[aa][ii],aa,cc+1);
	}
}
void dfs2(ll aa,ll bb,ll cc)
{
	if(ma<cc)
	{
		ma=max(ma,cc);
		jum=0;
	}
	if(ma==cc)
		jum++;
	ll ii;
	for(ii=0;ii<v[aa].size();ii++)
	{
		if(b[v[aa][ii]])continue;
		if(v[aa][ii]==bb)continue;
		dfs2(v[aa][ii],aa,cc+1);
	}
}
int main()
{
	ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>n;
	for(i=1;i<=n;i++)
	{
		cin>>ta>>tb;
		v[ta].pb(tb);
		v[tb].pb(ta);
	}
	dfs(1);
	CS=cyc.size();
	memset(b,0,sizeof(b));
	for(i=0;i<CS;i++)b[cyc[i]]=1;
	for(i=0;i<CS;i++)
	{
		ma=-1;
		jum=0;
		dfs1(cyc[i],cyc[i],0);
		A[i]=mp(ma,jum);
		//cout<<cyc[i]<<" "<<A[i].fi<<" "<<A[i].se<<"\n";
	}
	ma=-1;
	jum=0;
	for(i=0;i<CS;i++)
	{
		for(j=0;j<isi[i].size();j++)
			dfs2(isi[i][j],isi[i][j],0);
	}
	for(i=0;i<CS;i++)
	{
		ll tam=0;
		for(j=i+1;j<=(i+(CS)/2);j++)
		{
			if(ma<(tam+A[i].fi+A[j%CS].fi))
			{
				ma=(tam+A[i].fi+A[j%CS].fi);
				jum=0;
			}
			if(ma==(tam+A[i].fi+A[j%CS].fi))
			{
//				cout<<cyc[i]<<" "<<cyc[j%CS]<<" "<<ma<<"\n";
				jum+=A[i].se*A[j%CS].se;
			}
			tam++;
		}
		tam=0;
		for(j=i-1;j>=(i-(CS)/2);j--)
		{
			if(ma<(tam+A[i].fi+A[(j+CS)%CS].fi))
			{
				ma=(tam+A[i].fi+A[(j+CS)%CS].fi);
				jum=0;
			}	
			if(ma==(tam+A[i].fi+A[(j+CS)%CS].fi))
			{
		//		cout<<cyc[i]<<" "<<cyc[(j+CS)%CS]<<" "<<ma<<"\n";
				jum+=A[i].se*A[(j+CS)%CS].se;
			}
			tam++;
		}
	}
	//cout<<ma<<" "<<jum<<"\n";
	jum/=2;
	cout<<jum<<"\n";
}

Compilation message (stderr)

shymbulak.cpp: In function 'void dfs(ll)':
shymbulak.cpp:15:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ii=0;ii<v[aa].size();ii++)
           ~~^~~~~~~~~~~~~
shymbulak.cpp: In function 'void dfs1(ll, ll, ll)':
shymbulak.cpp:47:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ii=0;ii<v[aa].size();ii++)
           ~~^~~~~~~~~~~~~
shymbulak.cpp: In function 'void dfs2(ll, ll, ll)':
shymbulak.cpp:64:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(ii=0;ii<v[aa].size();ii++)
           ~~^~~~~~~~~~~~~
shymbulak.cpp: In function 'int main()':
shymbulak.cpp:97:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(j=0;j<isi[i].size();j++)
           ~^~~~~~~~~~~~~~

• Subtask 1: 0 / 30
• Subtask 2: 0 / 20
• Subtask 3: 0 / 50