Submission #533871

#	Time	Username	Problem	Language	Result	Execution time	Memory
533871		sare	Port Facility (JOI17_port_facility)	C++17	22 / 100	5981 ms	1048580 KiB

port_facility

//In the name of Allah :)
#include <bits/stdc++.h>
using namespace std;
string to_string(char c) { return string(1,c); }
string to_string(bool b) { return b ? "true" : "false"; }
string to_string(const char* s) { return (string)s; }
string to_string(string s) { return s; }
string to_string(vector<bool> v) { 
	string res = "{"; for(int i = 0; i < (int)v.size(); i++) res += char('0'+v[i]);
	res += "}"; return res; }
template<size_t SZ> string to_string(bitset<SZ> b) {
	string res = ""; for(size_t i = 0; i < SZ; i++) res += char('0'+b[i]);
	return res; }
template<class A, class B> string to_string(pair<A,B> p);
template<class T> string to_string(T v) { // containers with begin(), end()
	bool fst = 1; string res = "{";
	for (const auto& x: v) {
		if (!fst) res += ", ";
		fst = 0; res += to_string(x);
	}
	res += "}"; return res;
}
template<class A, class B> string to_string(pair<A,B> p) {
	return "("+to_string(p.first)+", "+to_string(p.second)+")"; }
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
	cerr << to_string(h); if (sizeof...(t)) cerr << ", ";
	DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define wis(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "] : [", DBG(__VA_ARGS__)
#else
#define wis(...) 0
#endif
typedef long long ll;
#define all(x) (x).begin(), (x).end()
const int MAXN = 2e6 + 10, MOD = 1e9 + 7;
int n, l[MAXN], r[MAXN], type[MAXN], pw[MAXN], comp;
vector<int> adj[MAXN];
vector<pair<int, int>> ver;
bitset<MAXN> mark, color;
bool bip = 1;

void dfs (int v, int c) {
	mark[v] = 1;
	color[v] = c;
	ver.push_back({l[v], r[v]});
	for (int i : adj[v]) {
		if (mark[i]) {
			bip &= color[i] != c;
		}
		else {
			dfs(i, c ^ 1);
		}
	}
}

int main() {
	ios::sync_with_stdio(0);
#ifndef LOCAL
	cin.tie(0);
#endif
	pw[0] = 1;
	for (int i = 1; i < MAXN; i++) {
		pw[i] = 2 * pw[i - 1] >= MOD ? 2 * pw[i - 1] - MOD : 2 * pw[i - 1];
	}

	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> l[i] >> r[i];
		type[l[i]] = type[r[i]] = i;
	}

	auto add_edge = [&](int v, int u) {
		adj[v].push_back(u);
		adj[u].push_back(v);
		//wis("add", u, v);
	};

	set<int> s;
	for (int i = 1; i < n + n; i++) {
		if (l[type[i]] == i) {
			s.insert(i);
		}
		else {
			s.erase(l[type[i]]);
			for (auto p = s.lower_bound(l[type[i]]); p != s.end(); p++) {
				add_edge(type[i], type[*p]);
			}
		}
	}


	for (int i = 0; i < n; i++) {
		if (mark[i] == 0) {
			comp++;
			dfs(i, 0);
			vector<int> tmp, stk[2];
			for (auto x : ver) {
				tmp.push_back(x.first);
				tmp.push_back(x.second);
			}
			ver.clear();

			sort(all(tmp));
			for (int x : tmp) {
				int ind = type[x];
				if (l[ind] == x) {
					stk[color[ind]].push_back(ind);
				}
				else {
					if (stk[color[ind]].back() != ind) {
						cout << 0 << '\n';
						return 0;
					}
					else {
						stk[color[ind]].pop_back();
					}
				}
			}
		}
	}
	if (bip == 0) {
		cout << 0 << '\n';
		return 0;
	}
	cout << pw[comp] << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22