제출 #1367352

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1367352		tigar	Love Polygon (BOI18_polygon)	C++20	100 / 100	121 ms	9436 KiB

polygon

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

map<string, int>conv;
int love[200005], indeg[200005], brr=1;
bool matched[200005];

int getid(string s)
{
    if(conv[s]==0){conv[s]=brr; brr++;}
    return conv[s];
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    int n;
    cin>>n;

    for(int i=0; i<n; i++)
    {
        string a, b;
        cin>>a>>b;
        int u=getid(a);
        int v=getid(b);
        love[u]=v;
    }

    if(n%2!=0){cout<<-1<<endl; return 0;}

    int cnt=0;

    for(int i=1; i<=n; i++)
    {
        if(!matched[i])
        {
            if (i!=love[i] && love[love[i]]==i)
            {
                matched[i]=true;
                matched[love[i]]=true;
                cnt+=2;
            }
        }
    }

    for(int i=1; i<=n; i++)if(!matched[i])indeg[love[i]]++;

    queue<int>q;
    for(int i=1; i<=n; i++)if(indeg[i]==0 && !matched[i])q.push(i);

    while(!q.empty())
    {
        int u=q.front();
        q.pop();
        if(matched[u])continue;
        int v=love[u];
        if(!matched[v])
        {
            matched[u]=true; matched[v]=true;
            cnt+=1;
            int t=love[v];
            if(!matched[t])
            {
                indeg[t]--;
                if(indeg[t]==0)q.push(t);
            }
        }
    }
    for(int i=1; i<=n; i++)
    {
        if (!matched[i])
        {
            int curr=i, s=0;
            while(!matched[curr])
            {
                matched[curr]=true;
                curr=love[curr];
                s++;
            }
            cnt+=(s/2);
        }
    }

    cout<<n-cnt<<"\n";
    return 0;
}

• 서브태스크 1: 21 / 21
• 서브태스크 2: 25 / 25
• 서브태스크 3: 29 / 29
• 서브태스크 4: 25 / 25