Submission #1190655

#	Time	Username	Problem	Language	Result	Execution time	Memory
1190655		mingga	Curtains (NOI23_curtains)	C++20	100 / 100	647 ms	89536 KiB

curtains

#include "bits/stdc++.h"

using namespace std;

#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define int long long
const int mod = 1e9 + 7;
const int inf = 2e18;
const int N = 5e5 + 7;
int n, m, k, ans[N];

struct segtree {
	int n;
	vector<int> st, lazy;
	segtree() {}
	segtree(int n): n(n) {
		st.resize(n * 4 + 4, 0);
		lazy.resize(n * 4 + 4, 0);
	}
	void down(int i) {
		if(lazy[i]) {
			int x = lazy[i]; lazy[i] = 0;
			st[i * 2] = max(st[i * 2], x);
			st[i * 2 + 1] = max(st[i * 2 + 1], x);
			lazy[i * 2] = max(lazy[i * 2], x);
			lazy[i * 2 + 1] = max(lazy[i * 2 + 1], x);
		}
	}
	void update(int i, int l, int r, int u, int v, int x) {
		if(l > v or r < u) return;
		if(u <= l and r <= v) {
			st[i] = max(st[i], x);
			lazy[i] = max(lazy[i], x);
			return;
		}
		down(i);
		int m = (l + r) >> 1;
		update(i * 2, l, m, u, v, x);
		update(i * 2 + 1, m + 1, r, u, v, x);
		st[i] = min(st[i * 2], st[i * 2 + 1]);
	}
	int get(int i, int l, int r, int u, int v) {
		if(l > v or r < u) return n + 1;
		if(u <= l and r <= v) {
			return st[i];
		}
		down(i);
		int m = (l + r) >> 1;
		return min(get(i * 2, l, m, u, v), get(i * 2 + 1, m + 1, r, u, v));
	}
	void update(int l, int r, int x) {
		update(1, 1, n, l, r, x);
	}
	int get(int l, int r) {
		return get(1, 1, n, l, r);
	}
} st;

vector<pair<int, int>> que[N];
vector<int> line[N];

signed main() {
	cin.tie(0) -> sync_with_stdio(0);
	#define task ""
	if(fopen(task ".INP", "r")) {
		freopen(task ".INP", "r", stdin);
		freopen(task ".OUT", "w", stdout);
	}
	cin >> n >> m >> k;
	for(int i = 1; i <= m; i++) {
		int l, r; cin >> l >> r;
		line[r].pb(l);
	}
	for(int i = 1; i <= k; i++) {
		int l, r; cin >> l >> r;
		que[r].pb({l, i});
	}
	st = segtree(n);
	for(int i = 1; i <= n; i++) {
		for(int l : line[i]) {
			st.update(l, i, l);
		}
		// cerr << "TURN " << i << ln;
		// for(int j = 1; j <= n; j++) {
		// 	cerr << st.get(j, j) << ' ';
		// }
		// cerr << ln;
		for(auto x : que[i]) {
			int l = x.fi, id = x.se;
			ans[id] = (st.get(l, i) >= l);
		}
	}
	for(int i = 1; i <= k; i++) {
		cout << (ans[i] ? "YES" : "NO") << ln;
	}
    cerr << "\nTime: " << clock() * 1000 / CLOCKS_PER_SEC;
}

Compilation message (stderr)

curtains.cpp: In function 'int main()':
curtains.cpp:71:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |                 freopen(task ".INP", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:72:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |                 freopen(task ".OUT", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 6 / 6
• Subtask 3: 15 / 15
• Subtask 4: 20 / 20
• Subtask 5: 36 / 36
• Subtask 6: 20 / 20