Submission #667487

#	Time	Username	Problem	Language	Result	Execution time	Memory
667487		flappybird	Rectangles (IOI19_rect)	C++17	100 / 100	4795 ms	713336 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
#include <cassert>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
#define MAX 2502
int N, M;
inline int trans(int i, int j) {
	return ((j * (j + 1)) >> 1) + i;
}
vector<short> axis[2][MAX * (MAX + 1) / 2];
vector<short> endp[2][MAX * (MAX + 1) / 2];
short l[MAX][MAX];
short r[MAX][MAX];
short d[MAX];
short u[MAX];
int ans = 0; void chk(short r1, short c1, short r2, short c2) {
	if (r1 > r2 || c1 > c2 || r2 >= N - 1 || c2 >= M - 1 || r1 <= 0 || c1 <= 0) return;
	short ind1, ind2;
	ind1 = lower_bound(axis[0][trans(r1, r2)].begin(), axis[0][trans(r1, r2)].end(), c1) - axis[0][trans(r1, r2)].begin();
	ind2 = lower_bound(axis[0][trans(r1, r2)].begin(), axis[0][trans(r1, r2)].end(), c2) - axis[0][trans(r1, r2)].begin();
	if (ind1 >= axis[0][trans(r1, r2)].size()) return;
	if (ind2 >= axis[0][trans(r1, r2)].size()) return;
	if (c1 != axis[0][trans(r1, r2)][ind1]) return;
	if (c2 != axis[0][trans(r1, r2)][ind2]) return;
	if (c2 - c1 != ind2 - ind1) return;
	ind1 = lower_bound(axis[1][trans(c1, c2)].begin(), axis[1][trans(c1, c2)].end(), r1) - axis[1][trans(c1, c2)].begin();
	ind2 = lower_bound(axis[1][trans(c1, c2)].begin(), axis[1][trans(c1, c2)].end(), r2) - axis[1][trans(c1, c2)].begin();
	if (ind1 >= axis[1][trans(c1, c2)].size()) return;
	if (ind2 >= axis[1][trans(c1, c2)].size()) return;
	if (r1 != axis[1][trans(c1, c2)][ind1]) return;
	if (r2 != axis[1][trans(c1, c2)][ind2]) return;
	if (r2 - r1 != ind2 - ind1) return;
	ans++;
}
long long count_rectangles(std::vector<std::vector<int> > A) {
	N = A.size();
	M = A[0].size();
	int i, j;
	memset(l, -1, sizeof(l));
	memset(r, -1, sizeof(r));
	for (i = 0; i < N; i++) {
		vector<pii> st;
		for (j = 0; j < M; j++) {
			int cc = 1;
			while (st.size() && st.back().first <= A[i][j]) {
				if (st.back().first == A[i][j]) cc = 0;
				if (st.back().second + 1 <= j) r[i][st.back().second] = j - 1;
				if (st.back().second + 1 <= j - 1) {
					axis[1][trans(st.back().second + 1, j - 1)].push_back(i);
					endp[1][trans(i, st.back().second + 1)].push_back(j - 1);
				}
				st.pop_back();
			}
			if (st.size()) l[i][j] = st.back().second + 1;
			if (cc && st.size() && st.back().second + 1 <= j - 1) {
				axis[1][trans(st.back().second + 1, j - 1)].push_back(i);
				endp[1][trans(i, st.back().second + 1)].push_back(j - 1);
			}
			st.emplace_back(A[i][j], j);
		}
	}
	vector<tuple<short, short, short, short>> v;
	for (i = 0; i < M; i++) {
		vector<pii> st;
		memset(u, -1, sizeof(u));
		memset(d, -1, sizeof(d));
		for (j = 0; j < N; j++) {
			int cc = 1;
			while (st.size() && st.back().first <= A[j][i]) {
				if (st.back().first == A[j][i]) cc = 0;
				if (st.back().second + 1 <= j) d[st.back().second] = j - 1;
				if (st.back().second + 1 <= j - 1) {
					axis[0][trans(st.back().second + 1, j - 1)].push_back(i);
					endp[0][trans(st.back().second + 1, i)].push_back(j - 1);
				}
				st.pop_back();
			}
			if (st.size()) u[j] = st.back().second + 1;
			if (cc && st.size() && st.back().second + 1 <= j - 1) {
				axis[0][trans(st.back().second + 1, j - 1)].push_back(i);
				endp[0][trans(st.back().second + 1, i)].push_back(j - 1);
			}
			st.emplace_back(A[j][i], j);
		}
		for (j = 1; j < N - 1; j++) if (~l[j][i] && ~r[j][i] && ~u[j] && ~d[j]) v.emplace_back(l[j][i], u[j], r[j][i], d[j]);
	}
	sort(v.begin(), v.end());
	v.erase(unique(v.begin(), v.end()), v.end());
	for (auto& [a, b, c, d] : v) chk(b, a, d, c);
	return ans;
}

Compilation message (stderr)

rect.cpp: In function 'void chk(short int, short int, short int, short int)':
rect.cpp:23:11: warning: comparison of integer expressions of different signedness: 'short int' and 'std::vector<short int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |  if (ind1 >= axis[0][trans(r1, r2)].size()) return;
      |      ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rect.cpp:24:11: warning: comparison of integer expressions of different signedness: 'short int' and 'std::vector<short int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |  if (ind2 >= axis[0][trans(r1, r2)].size()) return;
      |      ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rect.cpp:30:11: warning: comparison of integer expressions of different signedness: 'short int' and 'std::vector<short int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |  if (ind1 >= axis[1][trans(c1, c2)].size()) return;
      |      ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rect.cpp:31:11: warning: comparison of integer expressions of different signedness: 'short int' and 'std::vector<short int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |  if (ind2 >= axis[1][trans(c1, c2)].size()) return;
      |      ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 22 / 22
• Subtask 5: 10 / 10
• Subtask 6: 13 / 13
• Subtask 7: 28 / 28