Submission #770698

#	Time	Username	Problem	Language	Result	Execution time	Memory
770698		raysh07	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	1132 ms	32096 KiB

joioi

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF (int)1e18

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

int n, m;
const int N = 2005;
vector<vector<int>> a;
int p[N];
int mx = 0;

bool ok(int x){
	for (int i = 0; i < n; i++){
		p[i] = m;
		for (int j = 0; j < m; j++){
			if (abs(mx - a[i][j]) <= x);
			else {
			    p[i] = j;
			    break;
			}
		}
	}

	for (int i = 1; i < n; i++){
		p[i] = min(p[i] , p[i - 1]);
	}

	int ma = 0, mi = INF;
	for (int i = 0; i < n; i++){
		for (int j = p[i]; j < m; j++){
			mi = min(mi, a[i][j]);
			ma = max(ma, a[i][j]);
		}
	}

	return (ma - mi) <= x;
}

bool check(int x){
	for (int i1 = 0; i1 < 2; i1++){
		for (int i = 0; i < n; i++){
			reverse(a[i].begin(), a[i].end());
		}

		for (int i2 = 0; i2 < 2; i2++){
			for (int i = 0; i < n; i++){
				if (n - 1 - i > i){
					swap(a[i], a[n - 1 - i]);
				}
			}

			if (ok(x)) return true;
		}
	}

	return false;
}

void Solve()
{
	cin >> n >> m;
	a.resize(n);
	for (int i = 1; i <= n; i++) a[i - 1].resize(m);

	for (int i = 1; i <= n; i++){
		for (int j = 1; j <= m; j++){
			cin >> a[i - 1][j - 1], mx = max(mx, a[i - 1][j - 1]);
		}
	}

	int l = 0, r = 1e9;
	while (l != r){
		int mid = (l + r) / 2;

		if (check(mid)) r = mid;
		else l = mid + 1; 
	}

	cout << l << "\n";
}

int32_t main() 
{
    auto begin = std::chrono::high_resolution_clock::now();
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
  //  cin >> t;
    for(int i = 1; i <= t; i++) 
    {
        //cout << "Case #" << i << ": ";
        Solve();
    }
    auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
    return 0;
}

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