Submission #1300347

#	Time	Username	Problem	Language	Result	Execution time	Memory
1300347		KickingKun	Port Facility (JOI17_port_facility)	C++20	0 / 100	4 ms	332 KiB

port_facility

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ull unsigned long long
#define ld long double
#define bigint __int128
#define emb emplace_back
#define pb push_back
#define pii pair <int, int>
#define fi first
#define se second
#define all(v) v.begin(), v.end()
#define Task ""

#define MASK(k) (1ull << k)
#define bitcnt(k) __builtin_popcount(k)
#define testBit(n, k) ((n >> k) & 1)
#define flipBit(n, k) (n ^ (1ll << k))
#define offBit(n, k) (n & ~MASK(k))
#define onBit(n, k) (n | (1ll << k))

template <class T> bool minimize(T &a, T b) {if (a > b) {a = b; return true;} return false;}
template <class T> bool maximize(T &a, T b) {if (a < b) {a = b; return true;} return false;}

const int N = 1e6 + 5, LG = 20, mod = 1e9 + 7;
const ll INF = 1e18;

int n;
pii range[N];

namespace sub2 {
	vector <int> adj[N];
	int color[N];

	bool dfs(int u, int c) {
		color[u] = c;
		for (int v: adj[u]) {
			if (color[v] == color[u]) return false;
			if (color[v] == 0) {
				bool check = dfs(v, 3 - c);
				if (!check) return false;
			}
		}
		return true;
	}

	void solve() {
		sort (range + 1, range + n + 1);
		for (int u = 1; u <= n; u++) {
			for (int v = u + 1; v <= n; v++) {
				if (range[v].fi < range[u].se && range[u].se < range[v].se) {
					adj[u].emplace_back(v);
					adj[v].emplace_back(u);
				}
			}
		}

		int ans = 1;
		for (int u = 1; u <= n; u++) if (!color[u]) {
			bool check = dfs(u, 1);
			if (!check) return (void)(cout << 0);
			ans = ans * 2 % mod;
		}
		cout << ans;
	}
}

namespace sub34 {
	struct SegmentTree {
		vector <int> st;
		SegmentTree (int n) {
			st.assign(n * 4 + 5, 1e9);
		}

		void update(int id, int l, int r, int p, int val) {
			if (l == r) {
				st[id] = val;
				return;
			}
			int mid = (l + r) >> 1;
			if (p <= mid) update(id << 1, l, mid, p, val);
			else update(id << 1 | 1, mid + 1, r, p, val);
			st[id] = min(st[id << 1], st[id << 1 | 1]);
		}

		int get(int id, int l, int r, int u, int v) {
			if (u > r || v < l) return 1e9;
			if (u <= l && r <= v) return st[id];
			int mid = (l + r) >> 1;
			return min(get(id << 1, l, mid, u, v), get(id << 1 | 1, mid + 1, r, u, v));
		}
	};

	struct FenwickTree {
		vector <int> bit;
		FenwickTree (int len) {
			bit.assign(len + 1, 0);
		}

		void update(int p, int val) {
			for (; p < bit.size(); p += p & -p)
				bit[p] += val;
		}

		int get(int p) {
			int res = 0; for (; p > 0; p -= p & -p) res += bit[p];
			return res;
		}

		int get(int l, int r) {
			return get(r) - get(l - 1);
		}
	};

	int have_edge[N];
	int nearAffect[N], limit[N], spt[N][LG];

	int minR(int l, int r) {
		int k = __lg(r - l + 1);
		return min(spt[l][k], spt[r - (1 << k) + 1][k]);
	}

	bool cmp(int u, int v) {
		return range[u].se > range[v].se;
	}

	void solve() {
		sort (range + 1, range + n + 1);

		for (int i = 1; i <= n; i++) {
			int low = i + 1, high = n, lim = -1;
			while (low <= high) {
				int mid = (low + high) >> 1;
				if (range[mid].fi < range[i].se)
					low = (lim = mid) + 1;
				else high = mid - 1;
			}
			limit[i] = lim;
		}

		stack <int> st;
		for (int i = n; i > 0; i--) {
			while (!st.empty() && range[i].se > range[st.top()].se) st.pop();
			nearAffect[i] = (st.empty() ? -1 : st.top());
			if (nearAffect[i] > limit[i]) nearAffect[i] = -1;
			st.emplace(i);
		}

		vector <int> order(n); iota(all(order), 1);
		sort (all(order), cmp);

		int components = n;
		FenwickTree fen(n);
		SegmentTree ST(n);

		for (int i: order) {
			fen.update(i, 1);
			if (nearAffect[i] != -1) ST.update(1, 1, n, i, nearAffect[i]);
			if (limit[i] != -1) {
				int k = ST.get(1, 1, n, i + 1, limit[i]);
				if (k <= limit[i]) return (void)(cout << 0);

				// noi canh i->j (i < j <= limit[i] && B[i] < B[j])
				components -= fen.get(i + 1, limit[i]);
			}
		}

		int ans = 1;
		for (int i = 1; i <= components; i++)
			ans = ans * 2 % mod;
		cout << ans;
	}
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

	if (fopen(Task".inp", "r")) {
		freopen(Task".inp", "r", stdin);
		freopen(Task".out", "w", stdout);
	}

	cin >> n;
	for (int i = 1; i <= n; i++)
		cin >> range[i].fi >> range[i].se;

	sub34::solve();
}

Compilation message (stderr)

port_facility.cpp: In function 'int main()':
port_facility.cpp:180:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  180 |                 freopen(Task".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
port_facility.cpp:181:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  181 |                 freopen(Task".out", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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