Submission #1155914

#	Time	Username	Problem	Language	Result	Execution time	Memory
1155914		Alihan_8	The Kingdom of JOIOI (JOI17_joioi)	C++20	100 / 100	2591 ms	63300 KiB

joioi

#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()
#define ar array
#define pb push_back
#define ln '\n'
#define size(x) (int)(x).size()
#define int long long

using i64 = long long;

template <class F, class _S>
bool chmin(F &u, const _S &v){
	bool flag = false;
	if ( u > v ){
		u = v; flag |= true;
	}
	return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
	bool flag = false;
	if ( u < v ){
		u = v; flag |= true;
	}
	return flag;
}

signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int h, w; cin >> h >> w;
	
	vector <vector<int>> a(h, vector <int> (w));
	
	int mn = 1e9, mx = -mn;
	
	for ( auto &u: a ){
		for ( auto &v: u ){
			cin >> v;
			
			chmin(mn, v);
			chmax(mx, v);
		}
	}
	
	auto ok = [&](int d){
		vector <vector<int>> c(h, vector <int> (w, -1));
		
		for ( int i = 0; i < h; i++ ){
			for ( int j = 0; j < w; j++ ){
				if ( a[i][j] <= mn + d ){
					if ( a[i][j] >= mx - d ){
						continue;
					}
					
					c[i][j] = 0;
				} else{
					if ( mx - d > a[i][j] ) return false;
					
					c[i][j] = 1;
				}
			}
		}
		
		for ( auto x: {0, 1} ){
			int prv = -1, flag = true;
			
			for ( int i = 0; i < h; i++ ){
				int lst = prv, y = w;
				
				for ( int j = 0; j < w; j++ ){
					if ( c[i][j] == -1 ) continue;
					
					if ( c[i][j] == x ){
						chmax(lst, j);
					} else chmin(y, j);
				}
				
				if ( y <= lst ) flag = false;
				
				swap(prv, lst);
			}
			
			if ( flag ) return true;
		}
		
		for ( auto x: {0, 1} ){
			int prv = -1, flag = true;
			
			for ( int i = h - 1; i >= 0; i-- ){
				int lst = prv, y = w;
				
				for ( int j = 0; j < w; j++ ){
					if ( c[i][j] == -1 ) continue;
					
					if ( c[i][j] == x ){
						chmax(lst, j);
					} else chmin(y, j);
				}
				
				if ( y <= lst ) flag = false;
				
				swap(prv, lst);
			}
			
			if ( flag ) return true;
		}
		
		return false;
	};
	
	int l = 0, r = 1e9;
	
	while ( l < r ){
		int m = (l + r) / 2;
		
		if ( ok(m) ) r = m;
		else l = m + 1;
	}
	
	cout << l;
	
	cout << '\n';
}

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