Submission #266673

#	Time	Username	Problem	Language	Result	Execution time	Memory
266673		dennisstar	Rectangles (IOI19_rect)	C++17	10 / 100	2990 ms	233956 KiB

rect

#include <bits/stdc++.h>
#include "rect.h"
#define fi first
#define se second
#define em emplace
#define eb emplace_back
using namespace std;
using ll = long long;

struct dt {
	int a, b, c;
	dt() {}
	dt(int A, int B, int C) : a(A), b(B), c(C) {}
	bool operator <(const dt &r)const {
		return tie(a, b, c)<tie(r.a, r.b, r.c);
	}
	bool operator ==(const dt &r)const {
		return tie(a, b, c)==tie(r.a, r.b, r.c);
	}
};

int N, M, A;
vector<dt> H, V;

ll count_rectangles(vector<vector<int>> a) {
	N=a.size(); M=a[0].size();
	vector<vector<int>> l, r, u, d;
	for (int i=0; i<N; i++)
		l.eb(vector<int>(M, -1));
	r=u=d=l;

	for (int i=0; i<N; i++) {
		vector<int> st;
		for (int j=0; j<M; j++) {
			while (st.size()&&a[i][st.back()]<a[i][j]) st.pop_back();
			if (st.size()) H.eb(st.back(), j, i);
			st.eb(j);
		}
		st.clear();
		for (int j=M-1; j>=0; j--) {
			while (st.size()&&a[i][st.back()]<a[i][j]) st.pop_back();
			if (st.size()) H.eb(j, st.back(), i);
			st.eb(j);
		}
		st.clear();
		for (int j=0; j<M; j++) {
			while (st.size()&&a[i][st.back()]<=a[i][j]) st.pop_back();
			if (st.size()) l[i][j]=st.back();
			st.eb(j);
		}
		st.clear();
		for (int j=M-1; j>=0; j--) {
			while (st.size()&&a[i][st.back()]<=a[i][j]) st.pop_back();
			if (st.size()) r[i][j]=st.back();
			st.eb(j);
		}
	}

	for (int j=0; j<M; j++) {
		vector<int> st;
		for (int i=0; i<N; i++) {
			while (st.size()&&a[st.back()][j]<a[i][j]) st.pop_back();
			if (st.size()) V.eb(st.back(), i, j);
			st.eb(i);
		}
		st.clear();
		for (int i=N-1; i>=0; i--) {
			while (st.size()&&a[st.back()][j]<a[i][j]) st.pop_back();
			if (st.size()) V.eb(i, st.back(), j);
			st.eb(i);
		}
		st.clear();
		for (int i=0; i<N; i++) {
			while (st.size()&&a[st.back()][j]<=a[i][j]) st.pop_back();
			if (st.size()) u[i][j]=st.back();
			st.eb(i);
		}
		st.clear();
		for (int i=N-1; i>=0; i--) {
			while (st.size()&&a[st.back()][j]<=a[i][j]) st.pop_back();
			if (st.size()) d[i][j]=st.back();
			st.eb(i);
		}
	}

	sort(H.begin(), H.end());
	H.resize(unique(H.begin(), H.end())-H.begin());
	
	sort(V.begin(), V.end());
	V.resize(unique(V.begin(), V.end())-V.begin());

	for (int i=1; i<N-1; i++) for (int j=1; j<M-1; j++) {
		int L=l[i][j], R=r[i][j], U=u[i][j], D=d[i][j];
		if (L==-1||R==-1||U==-1||D==-1) continue;

		dt d1(L, R, U+1), d2(L, R, D-1);
		int b1=lower_bound(H.begin(), H.end(), d1)-H.begin();
		int b2=lower_bound(H.begin(), H.end(), d2)-H.begin();
		if (b1>=H.size()||d1<H[b1]) continue;
		if (b2>=H.size()||d2<H[b2]) continue;
		if (b2-b1!=D-U-2) continue;

		d1=dt(U, D, L+1), d2=dt(U, D, R-1);
		b1=lower_bound(V.begin(), V.end(), d1)-V.begin();
		b2=lower_bound(V.begin(), V.end(), d2)-V.begin();
		if (b1>=V.size()||d1<V[b1]) continue;
		if (b2>=V.size()||d2<V[b2]) continue;
		if (b2-b1!=R-L-2) continue;

		A++;
	}

	return A;
}

Compilation message (stderr)

rect.cpp: In function 'll count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:99:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<dt>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   99 |   if (b1>=H.size()||d1<H[b1]) continue;
      |       ~~^~~~~~~~~~
rect.cpp:100:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<dt>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |   if (b2>=H.size()||d2<H[b2]) continue;
      |       ~~^~~~~~~~~~
rect.cpp:106:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<dt>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |   if (b1>=V.size()||d1<V[b1]) continue;
      |       ~~^~~~~~~~~~
rect.cpp:107:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<dt>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  107 |   if (b2>=V.size()||d2<V[b2]) continue;
      |       ~~^~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 7
• Subtask 3: 0 / 12
• Subtask 4: 0 / 22
• Subtask 5: 10 / 10
• Subtask 6: 0 / 13
• Subtask 7: 0 / 28