Submission #666446

#	Time	Username	Problem	Language	Result	Execution time	Memory
666446		Augustyn	Love Polygon (BOI18_polygon)	C++14	54 / 100	88 ms	11212 KiB

polygon

#include<bits/stdc++.h>
using namespace std;
int n,a,b,il;
char wcz;
int pol[100001],lvl[100001],odp;
bool spar[100001];
queue<int>kol;
string s1,s2;
unordered_map<string,int>skal;
int main()
{
	cin>>n;
	ios_base::sync_with_stdio(0);
	if(n%2==1)
	{
		printf("-1");
		return 0;
	}
	for(int i=n;i;--i)
	{
		cin>>s1>>s2;
		if(skal[s1])
			a=skal[s1];
		else
		{
			++il;
			skal[s1]=il;
			a=il;
		}
		if(skal[s2])
			b=skal[s2];
		else
		{
			++il;
			skal[s2]=il;
			b=il;
		}
		pol[a]=b;
		++lvl[b];
	}
	for(int i=1;i<=il;++i)
	{
		if(lvl[i]==0)
			kol.push(i);
	}
	while(!kol.empty())
	{
		a=kol.front();
		kol.pop();
		if(pol[a]==a||spar[a])
			continue;
		if(spar[pol[a]]==0)
		{
			spar[pol[a]]=1;
			spar[a]=1;
			++odp;
			lvl[pol[a]]=0;
			--lvl[pol[pol[a]]];
			if(lvl[pol[pol[a]]]==0)
				kol.push(pol[pol[a]]);
		}
		else
		{
			++odp;
			spar[a]=1;
		}
		--lvl[pol[a]];
		if(lvl[pol[a]]==0)
			kol.push(pol[a]);
	}
	for(int i=1;i<=il;++i)
	{
		if(spar[i]==0)
		{
			int ter=pol[i];
			int wielk=1;
			spar[i]=1;
			while(ter!=i)
			{
				spar[ter]=1;
				ter=pol[ter];
				++wielk;
			}
			if(wielk!=2)
				odp+=wielk/2+(wielk%2);
		}
	}
	cout<<odp;
	return 0;
}

• Subtask 1: 0 / 21
• Subtask 2: 25 / 25
• Subtask 3: 29 / 29
• Subtask 4: 0 / 25