Submission #1190717

#	Time	Username	Problem	Language	Result	Execution time	Memory
1190717		Abdalaziz_Alshami	Love Polygon (BOI18_polygon)	C++20	0 / 100	763 ms	9048 KiB

polygon

#include<bits/stdc++.h>
using namespace std;
const int N=2e5+5;
int a[N];
signed main(){
	ios::sync_with_stdio(0); cin.tie(0);
	int n; cin>>n;
	map<string,int>m;
	int d=1;
	for(int i=0;i<n;i++){
		string u,v; cin>>u>>v;
		if(!m[u]) m[u]=d++; 
		if(!m[v]) m[v]=d++;
		a[m[u]]=m[v];
	}
	int ans=0;
	int vis[d]={0};
	for(int i=1;i<d;i++){
		int s=0;
		while(!vis[i]){
			vis[i]=1;
			i=a[i]; s++;
		}
		ans+=(s+1)/2;
	}
	if(n%2) cout<<-1;
	else cout<<ans;
}

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