Submission #1255120

#	Time	Username	Problem	Language	Result	Execution time	Memory
1255120		mingga	The Kingdom of JOIOI (JOI17_joioi)	C++20	100 / 100	545 ms	31844 KiB

joioi

// Author: caption_mingle
#include "bits/stdc++.h"

using namespace std;

#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define ll long long
const int mod = 1e9 + 7;
const int inf = 2e9;
const int N = 2005;
int n, m, a[N][N], b[N][N], mn;

bool check(int mid) {
	int mx_m = m;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= mx_m; j++) {
			if(a[i][j] > mn + mid) {
				mx_m = j - 1;
				break;
			}
			b[i][j] = 1;
		}
	}
	int mn1 = inf, mx1 = -inf;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= m; j++) {
			if(b[i][j]) {
				b[i][j] = 0;
				continue;
			}
			mn1 = min(mn1, a[i][j]);
			mx1 = max(mx1, a[i][j]);
		}
	}
	if(mx1 - mn1 <= mid or mx1 == -inf) return 1;
	mx_m = m;
	for(int i = n; i > 0; i--) {
		for(int j = 1; j <= mx_m; j++) {
			if(a[i][j] > mn + mid) {
				mx_m = j - 1;
				break;
			}
			b[i][j] = 1;
		}
	}
	mn1 = inf, mx1 = -inf;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= m; j++) {
			if(b[i][j]) {
				b[i][j] = 0;
				continue;
			}
			mn1 = min(mn1, a[i][j]);
			mx1 = max(mx1, a[i][j]);
		}
	}
	if(mx1 - mn1 <= mid or mx1 == -inf) return 1;
	int mn_m = 1;
	for(int i = n; i > 0; i--) {
		for(int j = m; j >= mn_m; j--) {
			if(a[i][j] > mn + mid) {
				mn_m = j + 1;
				break;
			}
			b[i][j] = 1;
		}
	}
	mn1 = inf, mx1 = -inf;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= m; j++) {
			if(b[i][j]) {
				b[i][j] = 0;
				continue;
			}
			mn1 = min(mn1, a[i][j]);
			mx1 = max(mx1, a[i][j]);
		}
	}
	if(mx1 - mn1 <= mid or mx1 == -inf) return 1;
	mn_m = 1;
	for(int i = 1; i <= n; i++) {
		for(int j = m; j >= mn_m; j--) {
			if(a[i][j] > mn + mid) {
				mn_m = j + 1;
				break;
			}
			b[i][j] = 1;
		}
	}
	mn1 = inf, mx1 = -inf;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= m; j++) {
			if(b[i][j]) {
				b[i][j] = 0;
				continue;
			}
			mn1 = min(mn1, a[i][j]);
			mx1 = max(mx1, a[i][j]);
		}
	}
	if(mx1 - mn1 <= mid or mx1 == -inf) return 1;
	return 0;
}

signed main() {
	cin.tie(0) -> sync_with_stdio(0);
	#define task ""
	if(fopen(task ".INP", "r")) {
		freopen(task ".INP", "r", stdin);
		freopen(task ".OUT", "w", stdout);
	}
	cin >> n >> m;
	mn = inf;
	for(int i = 1; i <= n; i++) {
		for(int j = 1; j <= m; j++) {
			cin >> a[i][j];
			mn = min(mn, a[i][j]);
		}
	}
	int l = 0, r = 1e9, ans;
	while(l <= r) {
		int m = (l + r) >> 1;
		if(check(m)) {
			ans = m;
			r = m - 1;
		} else l = m + 1;
	}
	cout << ans << ln;
    cerr << "\nTime: " << clock() * 1000 / CLOCKS_PER_SEC;
}

Compilation message (stderr)

joioi.cpp: In function 'int main()':
joioi.cpp:114:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  114 |                 freopen(task ".INP", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
joioi.cpp:115:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  115 |                 freopen(task ".OUT", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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