Submission #140843

#	Time	Username	Problem	Language	Result	Execution time	Memory
140843		DrumpfTheGodEmperor	The Kingdom of JOIOI (JOI17_joioi)	C++14	100 / 100	990 ms	39404 KiB

joioi

#include <bits/stdc++.h>
#define bp __builtin_popcountll
#define pb push_back
#define in(s) freopen(s, "r", stdin);
#define out(s) freopen(s, "w", stdout);
#define inout(s, end1, end2) freopen((string(s) + "." + end1).c_str(), "r", stdin),\
		freopen((string(s) + "." + end2).c_str(), "w", stdout);
#define fi first
#define se second
#define bw(i, r, l) for (int i = r - 1; i >= l; i--)
#define fw(i, l, r) for (int i = l; i < r; i++)
#define fa(i, x) for (auto i: x)
using namespace std;
const int mod = 1e9 + 7, inf = 1061109567;
const long long infll = 4557430888798830399;
const int N = 2005;
int h, w, a[N][N], mn = inf, mni = -1, mnj = -1, mxh[N], mnLand[N], mx = -1;
bool testBoard(int direction, int x) {
	if (direction == 0) {
		if (mnLand[mnj] < mni) return false;
		//Below area contains min, upper area contains max.
		int mnInMaxLand = inf;
		fw (j, 0, w) {
			bw (i, h, mnLand[j] + 1) mnInMaxLand = min(mnInMaxLand, a[i][j]); 
		}
		if (mx - mnInMaxLand <= x) return true;
		return false;
	} else {
		if (mnLand[mnj] > mni) return false;
		int mnInMaxLand = inf;
		fw (j, 0, w) {
			fw (i, 0, mnLand[j]) mnInMaxLand = min(mnInMaxLand, a[i][j]); 
		}
		if (mx - mnInMaxLand <= x) return true;
		return false;
	}
}
bool check(int x) {
	if (mx - mn <= x) return true;
	//Fix below area as land that contains the min element.
	fw (j, 0, w) {
		mxh[j] = -1;
		fw (i, 0, h) {
			if (a[i][j] > mn + x) break;
			mxh[j] = i;
		}
	}
	if (mxh[mnj] >= mni) {
		int curMx = h - 1;
		fw (j, 0, w) {
			//Make it decreasing from left to right.
			mnLand[j] = min(curMx, mxh[j]);
			curMx = min(curMx, mxh[j]);
		}
		if (testBoard(0, x)) return true;
		curMx = h - 1;
		bw (j, w, 0) {
			//Make it decreasing from left to right.
			mnLand[j] = min(curMx, mxh[j]);
			curMx = min(curMx, mxh[j]);
		}
		if (testBoard(0, x)) return true;
	}
	//Fix above area
	fw (j, 0, w) {
		mxh[j] = h;
		bw (i, h, 0) {
			if (a[i][j] > mn + x) break;
			mxh[j] = i;
		}
	}
	if (mxh[mnj] <= mni) {
		int curMx = 0;
		fw (j, 0, w) {
			//Make it decreasing from left to right.
			mnLand[j] = max(curMx, mxh[j]);
			curMx = max(curMx, mxh[j]);
		}
		if (testBoard(1, x)) return true;
		curMx = 0;
		bw (j, w, 0) {
			//Make it decreasing from left to right.
			mnLand[j] = max(curMx, mxh[j]);
			curMx = max(curMx, mxh[j]);
		}
		if (testBoard(1, x)) return true;
	}
	return false;
}
signed main() {
	#ifdef BLU
	in("blu.inp");
	#endif
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> h >> w;
	fw (i, 0, h) fw (j, 0, w) cin >> a[i][j];
	fw (i, 0, h) fw (j, 0, w) {
		if (a[i][j] < mn) {
			mn = a[i][j];
			mni = i, mnj = j;
		}
		mx = max(mx, a[i][j]);
	}
	int l = 0, r = 1e9;
	while (l < r) {
		int m = (l + r) >> 1;
		if (check(m)) r = m;
		else l = m + 1;
	}
	cout << l;
	return 0;
}

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