Submission #111986

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
111986	2019-05-17T03:48:02 Z	qkxwsm	The Kingdom of JOIOI (JOI17_joioi)	C++14	60 / 100	4000 ms	16352 KB

joioi

//clever
#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define DBG(x) cerr << #x << " = " << (x) << endl
#define SZ(x) ((int) ((x).size()))
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)

#define INF 1000000007
#define MAXN 2013

typedef pair<int, int> pii;

int N, M;
int grid[MAXN][MAXN];
int big, small = INF;
pii bigpos, smallpos;
int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, -1, 0, 1};
pii range[MAXN];
bitset<MAXN> cb[MAXN], cs[MAXN];

bool valid(int x, int y)
{
	return (0 <= x && x < N && 0 <= y && y < M);
}
bool ok()
{
	//these are the first guys that do not approve!
	FOR(i, 0, N)
	{
		if (range[i].fi >= range[i].se) return false;
	}
	bool flag = true; int pos = 0;
	FOR(i, 0, N)
	{
		//the guy can be in the range (range[i].fi, range[i].se)
		if (range[i].se < pos)
		{
			flag = false; break;
		}
		pos = max(pos, range[i].fi + 1);
	}
	if (flag) return true;
	flag = true; pos = M - 1;
	FOR(i, 0, N)
	{
		if (range[i].fi > pos)
		{
			flag = false; break;
		}
		pos = min(pos, range[i].se - 1);
	}
	if (flag) return true;
	return false;
}

bool check(int c)
{
	//try to merge stuff with small!
	FOR(i, 0, N)
	{
		cb[i].reset();
		cs[i].reset();
	}
	queue<pii> q;
	q.push(bigpos);
	cb[bigpos.fi][bigpos.se] = 1;
	while(!q.empty())
	{
		int x = q.front().fi, y = q.front().se;
		q.pop();
		FOR(d, 0, 4)
		{
			pii p = {x + dx[d], y + dy[d]};
			if (valid(p.fi, p.se) && (grid[p.fi][p.se] >= big - c) && !(cb[p.fi][p.se]))
			{
				q.push(p);
				cb[p.fi][p.se] = 1;
			}
		}
	}
	q.push(smallpos);
	cs[smallpos.fi][smallpos.se] = 1;
	while(!q.empty())
	{
		int x = q.front().fi, y = q.front().se;
		q.pop();
		FOR(d, 0, 4)
		{
			pii p = {x + dx[d], y + dy[d]};
			if (valid(p.fi, p.se) && (grid[p.fi][p.se] <= small + c) && !cs[p.fi][p.se])
			{
				q.push(p);
				cs[p.fi][p.se] = 1;
			}
		}
	}
	//try to have SMALL be an increasing/decreasing sequence!
	FOR(i, 0, N)
	{
		for (range[i].se = 0; range[i].se < M; range[i].se++)
		{
			if (!cs[i][range[i].se]) break;
		}
		for (range[i].fi = M - 1; range[i].fi >= 0; range[i].fi--)
		{
			if (!cb[i][range[i].fi]) break;
		}
	}
	if (ok())
	{
		return true;
	}
	//try to have BIG be an increasing/decreasing sequence
	FOR(i, 0, N)
	{
		for (range[i].se = 0; range[i].se < M; range[i].se++)
		{
			if (!cb[i][range[i].se]) break;
		}
		for (range[i].fi = M - 1; range[i].fi >= 0; range[i].fi--)
		{
			if (!cs[i][range[i].fi]) break;
		}
	}
	if (ok())
	{
		return true;
	}
	return false;
}

int32_t main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	// cout << fixed << setprecision(10);
	// cerr << fixed << setprecision(10);
	// if (fopen("file.in", "r"))
	// {
	// 	freopen ("file.in", "r", stdin);
	// 	freopen ("file.out", "w", stdout);
	// }
	cin >> N >> M;
	FOR(i, 0, N)
	{
		FOR(j, 0, M)
		{
			cin >> grid[i][j];
			if (grid[i][j] > big)
			{
				big = grid[i][j];
				bigpos = {i, j};
			}
			if (grid[i][j] < small)
			{
				small = grid[i][j];
				smallpos = {i, j};
			}
		}
	}
	// cerr << smallpos.fi << ' ' << smallpos.se << ' ' << bigpos.fi << ' ' << bigpos.se << endl;
	int lo = 0, hi = big - small;
	while(hi > lo)
	{
		int mid = (hi + lo) >> 1;
		if (check(mid)) hi = mid;
		else lo = mid + 1;
	}
	cout << lo << '\n';
	// cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
	return 0;
}
/* READ READ READ
* int overflow, maxn too small, special cases (n=1?, two distinct?), cin.tie() interactive
* reread the problem, try small cases
* note down possible sources of error as you go
* do smth instead of nothing
*/

Subtask #1

15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	384 KB	Output is correct
2	Correct	4 ms	384 KB	Output is correct
3	Correct	2 ms	384 KB	Output is correct
4	Correct	2 ms	384 KB	Output is correct
5	Correct	2 ms	384 KB	Output is correct
6	Correct	2 ms	384 KB	Output is correct
7	Correct	2 ms	384 KB	Output is correct
8	Correct	2 ms	384 KB	Output is correct
9	Correct	3 ms	384 KB	Output is correct
10	Correct	3 ms	384 KB	Output is correct
11	Correct	2 ms	384 KB	Output is correct
12	Correct	2 ms	384 KB	Output is correct
13	Correct	3 ms	384 KB	Output is correct
14	Correct	2 ms	384 KB	Output is correct

Subtask #2

45.0 / 45.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	384 KB	Output is correct
2	Correct	4 ms	384 KB	Output is correct
3	Correct	2 ms	384 KB	Output is correct
4	Correct	2 ms	384 KB	Output is correct
5	Correct	2 ms	384 KB	Output is correct
6	Correct	2 ms	384 KB	Output is correct
7	Correct	2 ms	384 KB	Output is correct
8	Correct	2 ms	384 KB	Output is correct
9	Correct	3 ms	384 KB	Output is correct
10	Correct	3 ms	384 KB	Output is correct
11	Correct	2 ms	384 KB	Output is correct
12	Correct	2 ms	384 KB	Output is correct
13	Correct	3 ms	384 KB	Output is correct
14	Correct	2 ms	384 KB	Output is correct
15	Correct	2 ms	384 KB	Output is correct
16	Correct	8 ms	1408 KB	Output is correct
17	Correct	40 ms	1408 KB	Output is correct
18	Correct	23 ms	1476 KB	Output is correct
19	Correct	25 ms	1528 KB	Output is correct
20	Correct	59 ms	1344 KB	Output is correct
21	Correct	88 ms	1528 KB	Output is correct
22	Correct	40 ms	1408 KB	Output is correct
23	Correct	39 ms	1408 KB	Output is correct
24	Correct	54 ms	1280 KB	Output is correct
25	Correct	75 ms	1408 KB	Output is correct
26	Correct	63 ms	1528 KB	Output is correct
27	Correct	89 ms	1408 KB	Output is correct
28	Correct	62 ms	1408 KB	Output is correct

Subtask #3

0 / 40.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	3 ms	384 KB	Output is correct
2	Correct	4 ms	384 KB	Output is correct
3	Correct	2 ms	384 KB	Output is correct
4	Correct	2 ms	384 KB	Output is correct
5	Correct	2 ms	384 KB	Output is correct
6	Correct	2 ms	384 KB	Output is correct
7	Correct	2 ms	384 KB	Output is correct
8	Correct	2 ms	384 KB	Output is correct
9	Correct	3 ms	384 KB	Output is correct
10	Correct	3 ms	384 KB	Output is correct
11	Correct	2 ms	384 KB	Output is correct
12	Correct	2 ms	384 KB	Output is correct
13	Correct	3 ms	384 KB	Output is correct
14	Correct	2 ms	384 KB	Output is correct
15	Correct	2 ms	384 KB	Output is correct
16	Correct	8 ms	1408 KB	Output is correct
17	Correct	40 ms	1408 KB	Output is correct
18	Correct	23 ms	1476 KB	Output is correct
19	Correct	25 ms	1528 KB	Output is correct
20	Correct	59 ms	1344 KB	Output is correct
21	Correct	88 ms	1528 KB	Output is correct
22	Correct	40 ms	1408 KB	Output is correct
23	Correct	39 ms	1408 KB	Output is correct
24	Correct	54 ms	1280 KB	Output is correct
25	Correct	75 ms	1408 KB	Output is correct
26	Correct	63 ms	1528 KB	Output is correct
27	Correct	89 ms	1408 KB	Output is correct
28	Correct	62 ms	1408 KB	Output is correct
29	Execution timed out	4083 ms	16352 KB	Time limit exceeded
30	Halted	0 ms	0 KB	-