Submission #837194

#	Time	Username	Problem	Language	Result	Execution time	Memory
837194		gustason	The Kingdom of JOIOI (JOI17_joioi)	C++14	100 / 100	618 ms	31692 KiB

joioi

#include <bits/stdc++.h>

using namespace std;
const int nax = 2001;
const int max_a = 1000000000;
int mat[nax][nax];
bool curr[nax][nax];

int mn = max_a, mx = 0;
int n, m;

void print() {
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < m; j++) {
			cout << mat[i][j] << " ";
		}
		cout << "\n";
	}
	cout << "\n";
}

void mini(int& a, int b) {
	a = min(a, b);
}

bool gali(int k) {
	int idx = 0;
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < m; j++) {
			// max priklauso [mx-k, mx]
			if (mx - k > mat[i][j]) {
				// (i, j) butinai priklauso TIK minimumams	
				idx = max(idx, j+1);
			}
		}
		
		// visi tarp tures buti minimumai [mn, mn+k]
		for(int j = 0; j < idx; j++) {
			if (mat[i][j] > mn + k) {
				return false;
			}
		}
	}
	return true;	
}

void flip1() {
	int aux[m][n];
	for(int i = 0; i < m; i++) {
		for(int j = 0; j < n; j++) {
			aux[i][j] = mat[j][m-i-1];
			//cout << i << " " << j << ": " << j << " " << n-i-1 << " " << aux[i][j] << "\n";
		}
	}
	swap(n, m);
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < m; j++){
			mat[i][j] = aux[i][j];
		}
	}
}

int go() {
	int l = 0, r = max_a, ans = max_a;
	while(l <= r) {
		int mid = (l + r) / 2;
		if (gali(mid)) {
			ans = mid;
			r = mid - 1;
		}
		else {
			l = mid + 1;
		}
	}
	return ans;
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	
	cin >> n >> m;

	for(int i = 0; i < n; i++) {
		for(int j = 0; j < m; j++) {
			cin >> mat[i][j];
		}
	}
	
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < m; j++) {
			mn = min(mn, mat[i][j]);
			mx = max(mx, mat[i][j]);
		}
	}
	
	//cout << mn << " " << mx << "\n";
	int ans = go();
	flip1();
	//print();
	mini(ans, go());
	
	flip1();
	//print();
	mini(ans, go());
	
	flip1();
	//print();
	mini(ans, go());
	
	cout << ans << "\n";
}

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