Submission #440748

#	Time	Username	Problem	Language	Result	Execution time	Memory
440748		arwaeystoamneg	Port Facility (JOI17_port_facility)	C++17	100 / 100	1200 ms	83308 KiB

port_facility

// EXPLOSION!
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
#include<chrono>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpll;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define mp make_pair
#define rsz resize
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define f first
#define s second
#define cont continue
#define endl '\n'
//#define ednl '\n'
#define test int testc;cin>>testc;while(testc--)
#define pr(a, b) trav(x,a)cerr << x << b; cerr << endl;
#define message cout << "Hello World" << endl;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; // for every grid problem!!
const ll linf = 4000000000000000000LL;
const ll inf = 1000000007;//998244353    

void pv(vi a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vll a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vector<vi>a) {
	F0R(i, sz(a)) { cout << i << endl; pv(a[i]); cout << endl; }
}void pv(vector<vll>a) { F0R(i, sz(a)) { cout << i << endl; pv(a[i]); }cout << endl; }void pv(vector<string>a) { trav(x, a)cout << x << endl; cout << endl; }
void setIO(string s) {
	ios_base::sync_with_stdio(0); cin.tie(0);
#ifdef arwaeystoamneg
	if (sz(s))
	{
		freopen((s + ".in").c_str(), "r", stdin);
		if (s != "test1")
			freopen((s + ".out").c_str(), "w", stdout);
	}
#endif
}
int n;
vpi a;
vi link;
int find(int i)
{
	return i == link[i] ? i : link[i] = find(link[i]);
}
void unite(int i, int j)
{
	link[find(i)] = find(j);
}
void merge(int i, int j)
{
	// connect i and j -> i means not j and j means not i ( like 2 - sat )
	unite(i, j + n);
	unite(i + n, j);
	if (find(i) == find(i + n) || find(j) == find(j + n))
	{
		cout << 0 << endl;
		exit(0);
	}
}
int main()
{
	setIO("test1");
	cin >> n;
	a.rsz(n);
	trav(x, a)cin >> x.f >> x.s;
	sort(all(a));
	link.rsz(2 * n);
	iota(all(link), 0);
	map<int, int>todo;
	F0R(i, n)
	{
		// find the range of segments intersecting the current range
		auto L = todo.lower_bound(a[i].f);
		auto R = todo.upper_bound(a[i].s);
		if (R != todo.begin())
		{
			auto R1 = R; R1--;
			while (L != R)
			{
				merge(i, L->s);
				// if the current one's link node is the same as the one at the end, all of them in between must have the same linke node. 
				if (find(R1->s) == find(L->s))break;
				L++;
			}
		}
		todo.insert({ a[i].s,i });
	}
	ll ans = 1;
	F0R(i, n)
	{
		if (find(i) == i)ans = (ans * 2) % inf;
	}
	cout << ans << endl;
}

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