Submission #481039

#	Time	Username	Problem	Language	Result	Execution time	Memory
481039		Kalashnikov	Port Facility (JOI17_port_facility)	C++17	22 / 100	4938 ms	1048580 KiB

port_facility

#include <bits/stdc++.h>
 
#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define all(a) a.begin() , a.end()
#define F first
#define S second
 
using namespace std;
using ll = long long;
 
const int N = 1e6+5 , inf = 2e9 + 7;
const ll INF = 1e18 ,   mod = 1e9+7 , P = 6547;

vector<int> g[N];
int u[N];

void dfs(int v , int col = 1) {
	u[v] = col;
	for(auto to: g[v]) {
		if(u[to] == 0) dfs(to , 3-col);
		else if(u[to] == col) {
			cout << 0;
			exit(0);
		}
	}
}

void solve(int tc) {
	int n;
	cin >> n;
	vector<pair<int,int>> v;
	for(int i = 1; i <= n; i ++) {
		int a , b;
		cin >> a >> b;
		v.push_back({a , b});
	}
	sort(all(v));

	set<pair<int,int>> st;
	int cnt = 0;
	for(int i = 0; i < v.size(); i ++) {
		pair<int,int> to = v[i];
		int last = 2*n;
		while(st.size() && st.begin()->F < v[i].F) {
			st.erase(*st.begin());
		}
		auto it = st.begin();
		while(it != st.end() && it->F < to.S) {
			if(v[it->S - 1].F >= last) {
				cout << 0;
				return;
			}
			last = v[it->S - 1].F;
			g[it->S].push_back(i+1);
			g[i+1].push_back(it->S);
			cnt ++;
			it ++;
		}
		st.insert({to.S , i+1});
	}

	ll ans = 1;
	for(int i = 1; i <= n; i ++) {
		if(u[i] == 0) {
			dfs(i);
			ans *= 2;
			ans %= mod;
		}
	}
	cout << ans;
}
/*
*/
main() {
    ios;
    int tt = 1 , tc = 0;
    // cin >> tt;
    while(tt --) {
        solve(++tc);
    }
    return 0;
}

Compilation message (stderr)

port_facility.cpp: In function 'void solve(int)':
port_facility.cpp:42:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |  for(int i = 0; i < v.size(); i ++) {
      |                 ~~^~~~~~~~~~
port_facility.cpp: At global scope:
port_facility.cpp:75:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   75 | main() {
      | ^~~~

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