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Submission #398117

# Submission time Handle Problem Language Result Execution time Memory
398117 2021-05-03T17:46:02 Z AmineWeslati Love Polygon (BOI18_polygon) C++14
54 / 100
 340 ms 15100 KB 
#include "bits/stdc++.h"
using namespace std; 

typedef long long ll;
typedef vector<int>vi;
#define pb push_back
#define sz(v) (int)v.size()
typedef string str;
#define FOR(i,a,b) for(int i=a; i<b; i++)

void IO(){
#ifdef LOCAL
	freopen("input.txt","r",stdin);
	freopen("output.txt","w",stdout);
#endif
}
//------------------------------------------------------//

void ckmin(int &x, int y){x=min(x,y);}

const int MX=2e5;
int N;
vi out(MX),in(MX,0);
map<str,int>mp;

vi vis(MX,0);


int main(){
	IO();

	cin>>N;
	int cnt=0;
	FOR(i,0,N){
		str s,ss; cin>>s>>ss;
		if(!mp.count(s)) mp[s]=cnt++;
		if(!mp.count(ss)) mp[ss]=cnt++;

		out[mp[s]]=mp[ss];
		in[mp[ss]]++;
	}
	if(N&1){
		cout << -1 << endl;
		return 0;
	}

	set<int>s;
	FOR(i,0,N) if(in[i]==0) s.insert(i);

	int ans=0;
	while(sz(s)){
		auto it=s.begin();
		int u=*it;
		s.erase(it);

		if(out[u]==u) continue;

		if(!vis[out[u]]){
			if(out[out[u]]!=out[u]){
				in[out[out[u]]]--;
				if(in[out[out[u]]]==0) s.insert(out[out[u]]);	
			}

			vis[u]=1; vis[out[u]]=1;
			out[out[u]]=u;
			ans++;
		}
	}

	FOR(i,0,N) if(!vis[i] && vis[out[i]]) out[i]=i;

	FOR(i,0,N){
		int n=0,cur=i;
		while(!vis[cur]){
			vis[cur]=1; n++;
			cur=out[cur];
		}
		if(n!=2) ans+=(n+1)/2;
	}
	cout << ans << endl;
	
	
}

Subtask #1
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2636 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 2 ms 2636 KB Output is correct
8 Incorrect 2 ms 2636 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 3 ms 2636 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 314 ms 10380 KB Output is correct
5 Correct 318 ms 10416 KB Output is correct
6 Correct 299 ms 10368 KB Output is correct
7 Correct 317 ms 10388 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 328 ms 11608 KB Output is correct
2 Correct 340 ms 11180 KB Output is correct
3 Correct 274 ms 10416 KB Output is correct
4 Correct 289 ms 10416 KB Output is correct
5 Correct 307 ms 10588 KB Output is correct
6 Correct 307 ms 12744 KB Output is correct
7 Correct 318 ms 12896 KB Output is correct
8 Correct 292 ms 12228 KB Output is correct
9 Correct 292 ms 13808 KB Output is correct
10 Correct 264 ms 15100 KB Output is correct
11 Correct 2 ms 2640 KB Output is correct
12 Correct 2 ms 2636 KB Output is correct
13 Correct 2 ms 2636 KB Output is correct
14 Correct 2 ms 2636 KB Output is correct

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2636 KB Output is correct
2 Correct 2 ms 2636 KB Output is correct
3 Correct 2 ms 2636 KB Output is correct
4 Correct 2 ms 2636 KB Output is correct
5 Correct 2 ms 2636 KB Output is correct
6 Correct 2 ms 2636 KB Output is correct
7 Correct 2 ms 2636 KB Output is correct
8 Incorrect 2 ms 2636 KB Output isn't correct
9 Halted 0 ms 0 KB -