Submission #1181090

#	Time	Username	Problem	Language	Result	Execution time	Memory
1181090		jbareja	The Kingdom of JOIOI (JOI17_joioi)	C++20	0 / 100	0 ms	320 KiB

joioi

#include <bits/stdc++.h>

using namespace std;

int H; // liczba wierszy
int W; // liczba kolumn

vector<vector<int>> altitude;
vector<vector<int>> occupation;
vector<vector<int>> cnt_x;
vector<vector<int>> cnt_o;

int maxi = 0, mini = 1e9+7;

void occupation_for_delta(int d) {
	for (int i=1; i<=H; i++) {
		for (int j=1; j<=W; j++) {
			const auto& now = altitude[i][j];
			bool first = abs(mini - now) <= d;
			bool second = abs(maxi - now) <= d;
			if (first && second) occupation[i][j] = 0;
			else if (first) occupation[i][j] = 1;
			else if (second) occupation[i][j] = 2;
			else occupation[i][j] = 3;
		}
	}
}

void count_prefix_sums() {
	for (int i=0; i<=H; i++) for (int j=0; j<=H; j++) cnt_x[i][j] = 0, cnt_o[i][j] = 0;
	for (int i=1; i<=H; i++) for (int j=1; j<=W; j++) {
		cnt_x[i][j] = cnt_x[i-1][j] + cnt_x[i][j-1] - cnt_x[i-1][j-1] + (occupation[i][j] == 1);;
		cnt_o[i][j] = cnt_o[i-1][j] + cnt_o[i][j-1] - cnt_o[i-1][j-1] + (occupation[i][j] == 2);
	}
}

int sum(vector<vector<int>>& cnt, int i1, int j1, int i2, int j2) {
	if (i1 > i2) swap(i1, i2);
	if (j1 > j2) swap(j1, j2);
	return cnt[i2][j2] - cnt[i1-1][j2] - cnt[i2][j1-1] + cnt[i1-1][j1-1];
}

bool check_quarter(int ip, int jp) {
	for (int i=1; i<=H; i++) for (int j=1; j<=H; j++)
		if (occupation[i][j] == 2 && sum(cnt_x, i, j, ip, jp)) return false;
	return true;
}

bool check_occupation() {
	for (int i=1; i<=H; i++) for (int j=1; j<=W; j++) if (occupation[i][j] == 3) return false;
	count_prefix_sums();
	if (check_quarter(1,1)) {
		// cout << "(1,1)\n";
		return true;
	}
	if (check_quarter(1,W)) {
		// cout << "(" << 1 << "," << W << ")\n";
		return true;
	}
	if (check_quarter(H,1)) {
		// cout << "(" << H << "," << 1 << ")\n";
		return true;
	}
	if (check_quarter(H,W)) {
		// cout << "(" << H << "," << W << ")\n";
		return true;
	}
	return false;
}

void print_occupation() {
	vector<char> temp = { '.', 'x', 'o', '@' };
	for (int i=1; i<=H; i++) {
		for (int j=1; j<=W; j++) cout << temp[occupation[i][j]];
		cout << '\n';
	}
}

void print_prefix_sums() {
	for (int i=1; i<=H; i++) {
		for (int j=1; j<=W; j++) cout << setw(3) << cnt_x[i][j] << ' ';
		cout << '\n';
	}
	cout << '\n';
	for (int i=1; i<=H; i++) {
		for (int j=1; j<=W; j++) cout << setw(3) << cnt_o[i][j] << ' ';
		cout << '\n';
	}
	cout << '\n';
}

int main() {
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

	cin >> H >> W;
	altitude.assign(H+1, vector<int>(W+1, 0));
	occupation.assign(H+1, vector<int>(W+1, 0));
	cnt_o.assign(H+1, vector<int>(W+1, 0));
	cnt_x.assign(H+1, vector<int>(W+1, 0));

	for (int i=1; i<=H; i++) for (int j=1; j<=W; j++) {
		cin >> altitude[i][j];
		maxi = max(maxi,altitude[i][j]);
		mini = min(mini, altitude[i][j]);
	}

	// int low = 0;
	// int high = maxi - mini;
	// while (low != high) {
	// 	int mid = (low + high) / 2;
	// 	occupation_for_delta(mid);
	// 	if (check_occupation()) high = mid;
	// 	else low = mid + 1;
	// }
	// cout << low << '\n';

	for (int i=0; i<=maxi-mini; i++) {

		// cout << "\ndelta = " << i << "\n"; // <=======

		occupation_for_delta(i);

		// cout << "check: " << check_occupation() << "\n"; // <=======

		// print_occupation(); // <========
		// cout << '\n'; // <========
		// print_prefix_sums(); // <========


		if (check_occupation()) {
			cout << i << '\n';
			return 0;
		}
	}
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 45
• Subtask 3: 0 / 40