oj.uz

Submission #1083764

# Submission time Handle Problem Language Result Execution time Memory
1083764 2024-09-04T05:30:42 Z IBory Love Polygon (BOI18_polygon) C++17
25 / 100
 135 ms 23604 KB 
#include <bits/stdc++.h>
#define pii pair<int, int>
using namespace std;

const int MAX = 100007;
pair<string, string> E[MAX];
int F[MAX], V[MAX], in[MAX], S[MAX];
vector<int> G[MAX];

int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	int N;
	cin >> N;

	if (N & 1) {
		cout << -1;
		return 0;
	}

	map<string, int> SN;
	for (int i = 1; i <= N; ++i) {
		string a, b;
		cin >> a >> b;
		SN[a] = i;
		E[i] = {a, b};
	}
	for (int i = 1; i <= N; ++i) F[SN[E[i].first]] = SN[E[i].second];

	int RN = 0, match = 0;
	for (int i = 1; i <= N; ++i) {
		if (i != F[i] && F[F[i]] == i) V[i] = 1;
		else RN++;
	}
	for (int i = 1; i <= N; ++i) {
		if (V[i] || V[F[i]]) continue;
		G[i].push_back(F[i]);
		in[F[i]]++;
	}

	queue<int> Q;
	for (int i = 1; i <= N; ++i) if (!G[i].empty() && !in[i]) Q.push(i);

	while (!Q.empty()) {
		int cur = Q.front(); Q.pop();
		if (V[F[cur]]) continue;
		if (!S[cur] && !S[F[cur]]) {
			match++;
			S[cur] = S[F[cur]] = 1;
		}
		if (!--in[F[cur]]) Q.push(F[cur]);
	}

	for (int i = 1; i <= N; ++i) {
		if (!in[i]) continue;
		int cur = i;
		vector<int> C = {S[cur]};
		while (1) {
			cur = F[cur];
			in[cur]--;
			if (cur == i) break;
			C.push_back(S[cur]);
		}

		// cout << "Cycle\n";
		// for (int n : C) cout << n << ' ';
		// cout << '\n';

		bool one = (*max_element(C.begin(), C.end()) == 1);
		if (!one) match += C.size() / 2;
		else {
			int piv = max_element(C.begin(), C.end()) - C.begin();
			for (int i = 0; i < C.size(); ++i) {
				int a = (piv + i) % C.size(), b = (piv + i + 1) % C.size();
				if (!S[C[a]] && !S[C[b]]) {
					match++;
					S[C[a]] = S[C[b]] = 1;
				}
			}
		}
	}

	int ans = RN - match;
	cout << ans;
	return 0;
}

Compilation message

polygon.cpp: In function 'int main()':
polygon.cpp:72:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |    for (int i = 0; i < C.size(); ++i) {
      |                    ~~^~~~~~~~~~

Subtask #1
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 9052 KB Output is correct
2 Correct 4 ms 9052 KB Output is correct
3 Correct 4 ms 9052 KB Output is correct
4 Correct 3 ms 9052 KB Output is correct
5 Correct 4 ms 9052 KB Output is correct
6 Correct 4 ms 8916 KB Output is correct
7 Correct 4 ms 9052 KB Output is correct
8 Incorrect 4 ms 9052 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 3 ms 9052 KB Output is correct
2 Correct 4 ms 9052 KB Output is correct
3 Correct 3 ms 9052 KB Output is correct
4 Correct 125 ms 23508 KB Output is correct
5 Correct 130 ms 23204 KB Output is correct
6 Correct 125 ms 23604 KB Output is correct
7 Correct 4 ms 9048 KB Output is correct

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 122 ms 23376 KB Output is correct
2 Correct 125 ms 23380 KB Output is correct
3 Correct 105 ms 22868 KB Output is correct
4 Correct 4 ms 9052 KB Output is correct
5 Correct 123 ms 23124 KB Output is correct
6 Correct 135 ms 23376 KB Output is correct
7 Correct 132 ms 23504 KB Output is correct
8 Correct 122 ms 23376 KB Output is correct
9 Correct 116 ms 23604 KB Output is correct
10 Correct 100 ms 22868 KB Output is correct
11 Correct 4 ms 9052 KB Output is correct
12 Incorrect 4 ms 9052 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #4
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 9052 KB Output is correct
2 Correct 4 ms 9052 KB Output is correct
3 Correct 4 ms 9052 KB Output is correct
4 Correct 3 ms 9052 KB Output is correct
5 Correct 4 ms 9052 KB Output is correct
6 Correct 4 ms 8916 KB Output is correct
7 Correct 4 ms 9052 KB Output is correct
8 Incorrect 4 ms 9052 KB Output isn't correct
9 Halted 0 ms 0 KB -