Submission #887049

#	Time	Username	Problem	Language	Result	Execution time	Memory
887049		fanwen	Curtains (NOI23_curtains)	C++17	0 / 100	68 ms	25548 KiB

curtains

/* author : bo may can 5 */

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define endl '\n'
#define file(name)                  \
    if(fopen(name".inp", "r"))      \
        freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout); 

const int MAX = 1e5 + 5;

int n, m, q;
vector <pair <int, int>> queries[MAX];
vector <int> events[MAX];

int ans[MAX], it[MAX << 2], lazy[MAX << 2];

void down(int idx) {
	if(lazy[idx] == 0) return;
	for (int i = 2 * idx; i <= 2 * idx + 1; ++i) {
		it[i] = max(it[i], lazy[idx]);
		lazy[i] = max(lazy[i], lazy[idx]);
	}
	lazy[idx] = 0;
}

void update(int idx, int l, int r, int u, int v, int val) {
	if(l > v || r < u) return;
	if(l >= u && r <= v) {
		it[idx] = max(it[idx], val);
		lazy[idx] = val;
		return;
	}

	down(idx);

	int mid = l + r >> 1;
	update(idx << 1, l, mid, u, v, val);
	update(idx << 1 | 1, mid + 1, r, u, v, val);

	it[idx] = min(it[idx << 1], it[idx << 1 | 1]);
}

int get(int idx, int l, int r, int u, int v) {
	if(l > v || r < u) return 1e9;

	if(l >= u && r <= v) return it[idx];

	down(idx);

	int mid = l + r >> 1;

	return min(get(idx << 1, l, mid, u, v), get(idx << 1 | 1, mid + 1, r, u, v));
}

void you_make_it(void) {
    cin >> n >> m >> q;
    for (int i = 1; i <= m; ++i) {
    	int l, r; cin >> l >> r;
    	events[r].emplace_back(l);
    }

    for (int i = 1; i <= q; ++i) {
    	int l, r; cin >> l >> r;
    	queries[r].emplace_back(l, i);
    }
    for (int r = 1; r <= n; ++r) {
    	for (auto l : events[r]) update(1, 1, n, l, r, l);
    	for (auto [l, i] : queries[r]) {
    		if(get(1, 1, n, l, r) >= l) ans[i] = 1;
    	}
    }
    for (int i = 1; i <= q; ++i) cout << (ans[i] ? "YES\n" : "NO\n");
}

signed main() {

#ifdef LOCAL
    freopen("TASK.inp", "r", stdin);
    freopen("TASK.out", "w", stdout);
#endif
    file("curtains");
    auto start_time = chrono::steady_clock::now();

    cin.tie(0), cout.tie(0) -> sync_with_stdio(0);

    you_make_it();

    auto end_time = chrono::steady_clock::now();

    cerr << "\nExecution time : " << chrono::duration_cast <chrono::milliseconds> (end_time - start_time).count() << "[ms]" << endl;

    return (0 ^ 0);
}

// Dream it. Wish it. Do it.

Compilation message (stderr)

curtains.cpp: In function 'void update(int, int, int, int, int, int)':
curtains.cpp:41:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   41 |  int mid = l + r >> 1;
      |            ~~^~~
curtains.cpp: In function 'int get(int, int, int, int, int)':
curtains.cpp:55:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   55 |  int mid = l + r >> 1;
      |            ~~^~~
curtains.cpp: In function 'int main()':
curtains.cpp:12:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |         freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:86:5: note: in expansion of macro 'file'
   86 |     file("curtains");
      |     ^~~~
curtains.cpp:12:49: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |         freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout);
      |                                          ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
curtains.cpp:86:5: note: in expansion of macro 'file'
   86 |     file("curtains");
      |     ^~~~

• Subtask 1: 0 / 3
• Subtask 2: 0 / 6
• Subtask 3: 0 / 15
• Subtask 4: 0 / 20
• Subtask 5: 0 / 36
• Subtask 6: 0 / 20