Submission #622377

#	Time	Username	Problem	Language	Result	Execution time	Memory
622377		Jomnoi	Rectangles (IOI19_rect)	C++17	38 / 100	5106 ms	123308 KiB

rect

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

const int MAX_W = 205;
const int MAX_N = 2505;
const int d[4][2] = {{-1, 0}, {0, -1}, {1, 0}, {0, 1}};

int N, M;
long long ans;
vector <vector <int>> A;
vector <vector <vector <int>>> maxRow, maxCol;
int qs[MAX_N][MAX_N];
bool visited[MAX_N][MAX_N];

long long count_rectangles(vector <vector <int>> a) {
	N = a.size(), M = a[0].size();
	A.resize(N + 1, vector <int> (M + 1, 0));
	if(min(N, M) < 3) {
		return 0;
	}

	int maxA = 0;
	for(int i = 0; i < N; i++) {
		for(int j = 0; j < M; j++) {
			A[i + 1][j + 1] = a[i][j];
			maxA = max(maxA, a[i][j]);
		}
	}
	
	if((N <= 700 and M <= 700) or (N <= 3 and M <= 2500)) {
		maxRow.resize(N + 1, vector <vector <int>> (M + 1, vector <int> (M + 1)));
		maxCol.resize(M + 1, vector <vector <int>> (N + 1, vector <int> (N + 1)));
		for(int r = 1; r <= N; r++) {
			for(int c = 1; c <= M; c++) {
				maxRow[r][c][c] = A[r][c];
			}
			for(int sz = 2; sz <= M; sz++) {
				for(int c1 = 1, c2 = sz; c2 <= M; c1++, c2++) {
					maxRow[r][c1][c2] = max(maxRow[r][c1 + 1][c2], maxRow[r][c1][c2 - 1]);
				}
			}
		}
		for(int c = 1; c <= M; c++) {
			for(int r = 1; r <= N; r++) {
				maxCol[c][r][r] = A[r][c];
			}
			for(int sz = 2; sz <= N; sz++) {
				for(int r1 = 1, r2 = sz; r2 <= N; r1++, r2++) {
					maxCol[c][r1][r2] = max(maxCol[c][r1 + 1][r2], maxCol[c][r1][r2 - 1]);
				}
			}
		}

		for(int r1 = 2; r1 <= N - 1; r1++) {
			for(int r2 = r1; r2 <= N - 1; r2++) {
				for(int c1 = 2; c1 <= M - 1; c1++) {
					bool okCol = true;
					for(int c2 = c1; c2 <= M - 1; c2++) {
						okCol &= (min(A[r1 - 1][c2], A[r2 + 1][c2]) > maxCol[c2][r1][r2]);
						
						bool okRow = true;
						for(int r3 = r1; r3 <= r2; r3++) {
							okRow &= (min(A[r3][c1 - 1], A[r3][c2 + 1]) > maxRow[r3][c1][c2]);
						}

						ans += (okCol == true and okRow == true);
					}
				}	
			}
		}
	}
	else {
		for(int i = 1; i <= N; i++) {
			for(int j = 1; j <= M; j++) {
				qs[i][j] = qs[i - 1][j] + qs[i][j - 1] - qs[i - 1][j - 1] + A[i][j];
			}
		}

		for(int i = 1; i <= N; i++) {
			for(int j = 1; j <= M; j++) {
				if(A[i][j] == 0 and visited[i][j] == false) {
					visited[i][j] = true;
					int minR = N, maxR = 1, minC = M, maxC = 1;
					queue <pair <int, int>> q;
					q.emplace(i, j);
					while(!q.empty()) {
						auto [ux, uy] = q.front();
						q.pop();

						minR = min(minR, ux);
						maxR = max(maxR, ux);
						minC = min(minC, uy);
						maxC = max(maxC, uy);
						for(int ii = 0; ii < 4; ii++) {
							int vx = ux + d[ii][0], vy = uy + d[ii][1];
							if(vx < 1 or vx > N or vy < 1 or vy > M) {
								continue;
							}

							if(visited[vx][vy] == false and A[vx][vy] == 0) {
								visited[vx][vy] = true;
								q.emplace(vx, vy);
							}
						}
					}

					if(minR > 1 and minC > 1 and maxR < N and maxC < M and qs[maxR][maxC] - qs[maxR][minC - 1] - qs[minR - 1][maxC] + qs[minR - 1][minC - 1] == 0) {
						ans++;
					}
				}
			}
		}
	}
	return ans;
}

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