Submission #298739

# Submission time Handle Problem Language Result Execution time Memory
298739 2020-09-13T22:48:01 Z eggag32 The Kingdom of JOIOI (JOI17_joioi) C++17
100 / 100
1773 ms 79096 KB
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define debug(x) cerr << #x << ": " << x << endl
#define debug2(x, y) debug(x), debug(y)
#define repn(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(i, a) for(int i = 0; i < (int)(a); i++)
#define all(v) v.begin(), v.end() 
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define sq(x) ((x) * (x))
const int mxN = 2005;

template<class T> T gcd(T a, T b){ return ((b == 0) ? a : gcd(b, a % b)); }

int h, w;
int g[mxN][mxN];
int mn[mxN][mxN], mn1[mxN][mxN];
int mx[mxN][mxN], mx1[mxN][mxN];
pi bst;

int solve(){
	//compute all the mins and maxes
	//mn and mx are for top
	//mn1 and mx1 are for bottom
	rep(j, w){
		mn[0][j] = g[0][j];
		mx[0][j] = g[0][j];
		repn(i, 1, h){
			mn[i][j] = min(mn[i - 1][j], g[i][j]);
			mx[i][j] = max(mx[i - 1][j], g[i][j]);
		}
	}
	rep(j, w){
		mn1[h - 1][j] = g[h - 1][j];
		mx1[h - 1][j] = g[h - 1][j];
		for(int i = h - 2; i >= 0; i--){
			mn1[i][j] = min(mn1[i + 1][j], g[i][j]);
			mx1[i][j] = max(mx1[i + 1][j], g[i][j]);
		}
	}
	int ans = 2e9;
	vi lev(w, h);
	rep(i, bst.se + 1) lev[i] = bst.fi;
	int maxEl = 0;
	for(int i = h - 1; i >= bst.fi; i--){
		rep(j, bst.se + 1) maxEl = max(maxEl, g[i][j]);
	}
	//now we do the initial extension
	int mx2 = 0, mx3 = 0;
	int mn2 = 2e9, mn3 = 2e9;
	while(lev[0] > 0 && g[lev[0] - 1][0] <= maxEl) lev[0]--;
	repn(i, 1, w){
		 while(lev[i] > 0 && lev[i] > lev[i - 1] && g[lev[i] - 1][i] <= maxEl){
		 	lev[i]--;
		 }
	}
	rep(j, w){
		if(lev[j] != h){
			mx2 = max(mx2, mx1[lev[j]][j]);
			mn2 = min(mn2, mn1[lev[j]][j]);
		}
		if(lev[j]){
			mx3 = max(mx3, mx[lev[j] - 1][j]);
			mn3 = min(mn3, mn[lev[j] - 1][j]);
		}
	}
	ans = min(ans, max(mx3 - mn3, mx2 - mn2));
	int cur = 0;
	while(true){
		//move the pointer if we finished the last col
		while(cur < w && !lev[cur]) cur++;
		if(cur == w) break;
		int mnxt = 2e9;
		rep(j, w){
			if(lev[j] && (!j || (j && lev[j] > lev[j - 1]))){
				mnxt = min(mnxt, g[lev[j] - 1][j]);
			}
		}
		maxEl = max(maxEl, mnxt);
		int mx2 = 0, mx3 = 0;
		int mn2 = 2e9, mn3 = 2e9;
		while(lev[0] > 0 && g[lev[0] - 1][0] <= maxEl) lev[0]--;
		repn(i, 1, w){
			 while(lev[i] > 0 && lev[i] > lev[i - 1] && g[lev[i] - 1][i] <= maxEl){
			 	lev[i]--;
				if(cur == (w - 1) && i == (w - 1)) break;
			 }
		}
		if(cur == (w - 1) && !lev[cur]) break;
		rep(j, w){
			if(lev[j] != h){
				mx2 = max(mx2, mx1[lev[j]][j]);
				mn2 = min(mn2, mn1[lev[j]][j]);
			}
			if(lev[j]){
				mx3 = max(mx3, mx[min(h - 1, lev[j] - 1)][j]);
				mn3 = min(mn3, mn[min(h - 1, lev[j] - 1)][j]);
			}
		}
		//update answer
		ans = min(ans, max(mx3 - mn3, mx2 - mn2));
	}
	return ans;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	//freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
	cin >> h >> w;
	rep(i, h) rep(j, w) cin >> g[i][j];
	int mn0 = 2e9;
	rep(i, h) rep(j, w) if(g[i][j] < mn0){
		mn0 = g[i][j];
		bst = mp(i, j);
	}
	int ans = solve();
	bst = {h - 1 - bst.fi, bst.se};
	rep(i, h / 2) rep(j, w) swap(g[i][j], g[h - i - 1][j]);
	ans = min(ans, solve());
	bst = {bst.fi, w - 1 - bst.se};
	rep(i, h) rep(j, w / 2) swap(g[i][j], g[i][w - j - 1]);
	ans = min(ans, solve());
	rep(i, h / 2) rep(j, w) swap(g[i][j], g[h - i - 1][j]);
	bst = {h - 1 - bst.fi, bst.se};
	ans = min(ans, solve());
	cout << ans << endl;
	return 0;
}
/*
Things to look out for:
	- Integer overflows
	- Array bounds
	- Special cases
Be careful!
*/
# Verdict Execution time Memory Grader output
1 Correct 1 ms 512 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 1 ms 640 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 1 ms 512 KB Output is correct
13 Correct 1 ms 512 KB Output is correct
14 Correct 1 ms 640 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 512 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 1 ms 640 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 1 ms 512 KB Output is correct
13 Correct 1 ms 512 KB Output is correct
14 Correct 1 ms 640 KB Output is correct
15 Correct 1 ms 672 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 8 ms 5120 KB Output is correct
18 Correct 9 ms 5120 KB Output is correct
19 Correct 9 ms 5120 KB Output is correct
20 Correct 7 ms 4608 KB Output is correct
21 Correct 8 ms 5120 KB Output is correct
22 Correct 9 ms 5120 KB Output is correct
23 Correct 9 ms 5248 KB Output is correct
24 Correct 8 ms 4608 KB Output is correct
25 Correct 9 ms 5120 KB Output is correct
26 Correct 9 ms 5120 KB Output is correct
27 Correct 8 ms 5120 KB Output is correct
28 Correct 9 ms 5120 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 512 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 512 KB Output is correct
6 Correct 1 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 1 ms 640 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 1 ms 512 KB Output is correct
13 Correct 1 ms 512 KB Output is correct
14 Correct 1 ms 640 KB Output is correct
15 Correct 1 ms 672 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 8 ms 5120 KB Output is correct
18 Correct 9 ms 5120 KB Output is correct
19 Correct 9 ms 5120 KB Output is correct
20 Correct 7 ms 4608 KB Output is correct
21 Correct 8 ms 5120 KB Output is correct
22 Correct 9 ms 5120 KB Output is correct
23 Correct 9 ms 5248 KB Output is correct
24 Correct 8 ms 4608 KB Output is correct
25 Correct 9 ms 5120 KB Output is correct
26 Correct 9 ms 5120 KB Output is correct
27 Correct 8 ms 5120 KB Output is correct
28 Correct 9 ms 5120 KB Output is correct
29 Correct 1585 ms 75128 KB Output is correct
30 Correct 1559 ms 78840 KB Output is correct
31 Correct 1738 ms 78980 KB Output is correct
32 Correct 1606 ms 79096 KB Output is correct
33 Correct 1586 ms 69404 KB Output is correct
34 Correct 1709 ms 78968 KB Output is correct
35 Correct 1697 ms 79004 KB Output is correct
36 Correct 1663 ms 78460 KB Output is correct
37 Correct 1773 ms 79008 KB Output is correct