Submission #94926

#	Time	Username	Problem	Language	Result	Execution time	Memory
94926		noclever	Untitled (POI11_kon)	C++14	Compilation error	0 ms	0 KiB

Main

#include <vector>
#include <iostream>
#include <set>
#include <bitset>
using namespace std;

int n;
vector< vector<short> > g, tg;
vector< bitset<5001> > mat;
vector<int> was, topoSort, scc;
int cur = 1;
vector<int> as;
vector<int> st;
vector<short> x[2];
int cnt[2][2];

void reverse_graph() {
	for (int u = 1; u < 2 * n + 1; u++) {
		for (auto& v : g[u]) {
			tg[v].push_back(u);
		}
		vector<short>().swap(g[u]);
	}
}

void add_edge(int u, int v) {
	g[u].push_back(v);
}

void dfs1(int u) {
	was[u] = 1;
	for (auto& v : g[u]) {
		if (!was[v]) {
			dfs1(v);
		}
	}
	topoSort.push_back(u);
}

void dfs2(int u) {
	scc[u] = cur;
	was[u] = 1;
	for (auto& v : tg[u]) {
		if (!was[v]) {
			dfs2(v);
		}
	}
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> n;
	mat.assign(n + 1, bitset<5001>());
	g.resize(2 * n + 1);
	tg.resize(2 * n + 1);
	for (int i = 1; i <= n; i++) {
		int k;
		cin >> k;
		while (k--) {
			int a;
			cin >> a;
			mat[a][i] = mat[i][a] = 1;
		}
	}
	for (int i = 1; i <= n - 1; i++) {
		for (int j = i + 1; j <= n; j++) {
			if (mat[i][j]) {
				add_edge(i, j + n);
				add_edge(j, i + n);
			}
			else {
				add_edge(i + n, j);
				add_edge(j + n, i);
			}
		}
	}
	was.assign(2 * n + 1, 0);
	for (int i = 1; i <= 2 * n; i++) {
		if (!was[i]) {
			dfs1(i);
		}
	}
	reverse(topoSort.begin(), topoSort.end());
	reverse_graph();
	scc.assign(2 * n + 1, -1);
	was.assign(2 * n + 1, 0);
	for (auto& u : topoSort) {
		if (!was[u]) {
			dfs2(u);
			cur++;
		}
	}
	as.resize(n + 1);
	for (int i = 1; i <= n; i++) {
		if (scc[i] == scc[i + n]) {
			cout << 0 << '\n';
			return 0;
		}
		as[i] = scc[i] > scc[i + n];
	}
	int ans = 1;
	int sup = 0, con = 0;
	for (int i = 1; i <= n; i++) {
		sup += 1 - as[i];
		con += as[i];
		x[1 - as[i]].push_back(i);
	}

	if ((sup == 0) || (con == 0)) {
		ans = 0;
	}

	st.resize(n + 1);

	for (auto& u : x[0]) {
		for (auto& v : x[1]) {
			int idx = mat[u][v] ? v : u;
			int idx2 = mat[u][v] ? u : v;
			if (st[idx] > 0) {
				st[idx] = -1;
			} else if (st[idx] == 0) {
				st[idx] = idx2;
			}
		}
	}

	for (int i = 1; i <= n; i++) {
		if (st[i] == 0) {
			if ((as[i]) && (con > 1)) ans++;
			if ((!as[i]) && (sup > 1)) ans++;
		}
	}
	
	for (int i = 0; i < 2; i++) {
		for (auto& u : x[i]) {
			if (st[u] == 0) {
				cnt[i][0]++;
			}
			else if (st[u] > 0) {
				cnt[i][1]++;
			}
		}
	}

	ans += cnt[0][0] * cnt[1][1] + cnt[0][1] * cnt[1][0];
	


	cout << ans << '\n';
	return 0;
}

Compilation message (stderr)

kon.cpp: In function 'int main()':
kon.cpp:84:2: error: 'reverse' was not declared in this scope
  reverse(topoSort.begin(), topoSort.end());
  ^~~~~~~