Submission #1047803

#	Time	Username	Problem	Language	Result	Execution time	Memory
1047803		vjudge1	Rectangles (IOI19_rect)	C++17	23 / 100	123 ms	98712 KiB

rect

#include "rect.h"
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define pb push_back
#define ff first
#define all(x) x.begin(), x.end()
#define ss second
const int N = 2600, K = 20;
int rmqq[N][K];
int rmq[N][N][K], rmq2[N][N][K];

int get(int l, int r){
	int k = int(log2(r-l+1));
	return max(rmqq[l][k], rmqq[r-(1<<k)+1][k]);
}
int gett(int l, int r, int sat){
	int k = int(log2(r-l+1));
	return max(rmq2[sat][l][k], rmq2[sat][r-(1<<k)+1][k]);
}
int gett2(int l, int r, int sat){
	int k = int(log2(r-l+1));
	return max(rmq[sat][l][k], rmq[sat][r-(1<<k)+1][k]);
}
long long count_rectangles(std::vector<std::vector<int> > a) {
	int n = a.size();
	int m = a[0].size();

	if(n < 3 || m < 3){
		return 0;
	}

	if(n == 3){
		vector<bool> good(m);
		for(int i = 1; i + 1 < m; ++i){
			if(a[1][i] < a[0][i] && a[1][i] < a[2][i]){
				good[i] = 1;
			}else good[i] = 0;
		}

		for(int i = 1; i < m; ++i) rmqq[i][0] = (good[i] ? a[1][i] : INT_MAX);
		for(int j = 1; j < K; ++j){
			for(int i = 1; i + (1<<j) <= m; ++i){
				rmqq[i][j] = max(rmqq[i][j - 1], rmqq[i+(1<<(j-1))][j-1]);
			}
		}
		int ans = 0;
		for(int i = 1; i + 1 < m; ++i){
			for(int j = i; j + 1 < m; ++j){
				if(get(i, j) < min(a[1][i - 1], a[1][j + 1]) && good[i]){
					++ans;
				}
			}
		}

		return ans;
	}
	int mx = 0;
	for(int i = 0; i < n; ++i) for(int j = 0; j < m; ++j) mx = max(mx, a[i][j]);
	if(mx <= 1){
		vector<vector<int>> dp(n, vector<int>(m));
		vector<vector<int>> dp2(n, vector<int>(m));
		ll ans = 0;
		for(int j = 1; j + 1 < m; ++j) dp[0][j] = (a[0][j] == 0 ? -n*m*5 : 0);
		for(int i = 1; i + 1 < n; ++i){
			for(int j = 0; j < m; ++j){
				if(a[i][j] == 1){
					dp[i][j] = 0;
					dp2[i][j] = dp2[i - 1][j] + 1;
				}else{
					dp[i][j] = dp[i - 1][j] + 1;
					dp2[i][j] = 0;
				}
			}
		}
		// for(int i = 0; i < n; ++i){
		// 	for(int j = 0; j < m; ++j) cout << a[i][j];
		// 	cout << '\n';
		// }
		for(int i = 1; i + 1 < n; ++i){
			int r = 1;
			for(int j = 1; j + 1 < m; ++j){
				// cout << i << ' ' << j << '\n';
				if(a[i][j] == 1) continue;
				// cout << i << ' ' << j << '\n';
				if(a[i][j - 1] != 1) continue;
				if(a[i + 1][j] != 1) continue;
				r = j;
				while(r + 1 < m && a[i][r] == 0 && a[i + 1][r] == 1) ++r;
				--r;
				if(a[i][r + 1] != 1){
					j = r;
					continue;
				}

				ll sum = 0;
				int mx = dp[i][j];
				if(mx < 0){
					j = r;
					continue;
				}
				int ok = 1;

				vector<pair<int, ll>> v;
				for(int l = j; l <= r; ++l){
					// int co = 1;
					// while(!v.empty() && v.back().first > dp[i][l]){
					// 	co += v.back().second;
					// 	sum -= v.back().first * v.back().second;
					// 	v.pop_back();
					// }
					// sum += dp[i][l] * co;
					// v.pb({dp[i][l], co});
					if(dp[i][l] != mx) ok = 0;
				}
				// cout << ok;
				// cout << i << ' ' << j-1 << ' ';
				// cout <<dp2[i][j-1] << ' ';
				ans += ok && dp2[i][j - 1] >= dp[i][j] && dp2[i][r + 1] >= dp[i][j];

				// cout << i << ' ' << j << ' ' << r << ' ' << ans << '\n';

				j = r;
			}
		}
		return ans;
	}
	for(int l = 0; l < n; ++l){
		for(int i = 0; i < m; ++i) rmq[l][i + 1][0] = a[l][i];
		for(int j = 1; j < K; ++j){
			for(int i = 1; i + (1<<j) <= m + 1; ++i){
				rmq[l][i][j] = max(rmq[l][i][j - 1], rmq[l][i+(1<<(j-1))][j-1]);
			}
		}
	}
	for(int l = 0; l < m; ++l){
		for(int i = 0; i < m; ++i) rmq2[l][i + 1][0] = a[i][l];
		for(int j = 1; j < K; ++j){
			for(int i = 1; i + (1<<j) <= n + 1; ++i){
				rmq2[l][i][j] = max(rmq2[l][i][j - 1], rmq2[l][i+(1<<(j-1))][j-1]);
			}
		}
	}
	int ans = 0;
	for(int i =1; i + 1< n; ++i){
		for(int i1 = i; i1 + 1 < n; ++i1){
			for(int j = 1; j + 1 < m; ++j){
				for(int j1 = j; j1 + 1 < m; ++j1){
					bool ok = 1;
					for(int l = j; l <= j1; ++l){
						if(gett(i, i1, l) >= min(a[i1 + 1][l], a[i - 1][l])){
							ok = 0;
						}
					}
					for(int l = i; l <= i1; ++l){
						if(gett2(j, j1, l) >= min(a[l][j1 + 1], a[l][j - 1])){
							ok = 0;
						}
					}
					ans += ok;
				}
			}
		}
	}
	return ans;
}

Compilation message (stderr)

rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:96:8: warning: unused variable 'sum' [-Wunused-variable]
   96 |     ll sum = 0;
      |        ^~~

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