Submission #109262

#	Time	Username	Problem	Language	Result	Execution time	Memory
109262		qkxwsm	Luxury burrow (IZhO13_burrow)	C++14	100 / 100	756 ms	18160 KiB

burrow

//clever
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;

random_device(rd);
mt19937 rng(rd());
const long long FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();

struct custom_hash
{
	template<class T>
	unsigned long long operator()(T v) const
	{
		unsigned long long x = v;
		x += FIXED_RANDOM;
		// x += 11400714819323198485ull;
		// x = (x ^ (x >> 30)) * 13787848793156543929ull;
		x = (x ^ (x >> 27)) * 10723151780598845931ull;
		return x ^ (x >> 31);
	}
};

template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T, class U> using hash_table = gp_hash_table<T, U, custom_hash>;

template<class T>
T randomize(T mod)
{
	return (uniform_int_distribution<T>(0, mod - 1))(rng);
}
template<class T>
void readi(T &x)
{
	x = 0;
	bool negative = false;
	char c = ' ';
	while (c < '-')
	{
		c = getchar();
	}
	if (c == '-')
	{
		negative = true;
		c = getchar();
	}
	while (c >= '0')
	{
		x = x * 10 + (c - '0');
		c = getchar();
	}
	if (negative)
	{
		x = -x;
	}
}
template<class T>
void printi(T output)
{
	if (output == 0)
	{
		putchar('0');
		return;
	}
	if (output < 0)
	{
		putchar('-');
		output = -output;
	}
	int buf[20], n = 0;
	while(output)
	{
		buf[n] = ((output % 10));
		output /= 10;
		n++;
	}
	for (n--; n >= 0; n--)
	{
		putchar(buf[n] + '0');
	}
	return;
}
template<class T>
void ckmin(T &a, T b)
{
	a = min(a, b);
}
template<class T>
void ckmax(T &a, T b)
{
	a = max(a, b);
}
long long expo(long long a, long long e, long long mod)
{
	return ((e == 0) ? 1 : ((expo(a * a % mod, e >> 1, mod)) * ((e & 1) ? a : 1) % mod));
}
template<class T, class U>
void nmod(T &x, U mod)
{
	if (x >= mod) x -= mod;
}
template<class T>
T gcd(T a, T b)
{
	return (b ? gcd(b, a % b) : a);
}

#define y0 ___y0
#define y1 ___y1
#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#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 ALL(x) (x).begin(), (x).end()

const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-9;

#define MAGIC 347
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll
#define MAXN 1013

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pdd;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
typedef vector<pdd> vpd;

int N, M, K;
int grid[MAXN][MAXN];
int rt[MAXN][MAXN];

int calc(vi v)
{
	//find the next guy to the left of this thats < this
	//find the next guy to the right thats < this
	vi lt(SZ(v)), rt(SZ(v));
	vpi mins;
	mins.PB({-INF, -1});
	FOR(i, 0, SZ(v))
	{
		int x = v[i];
		while(mins.back().fi >= x) mins.pop_back();
		lt[i] = mins.back().se;
		mins.PB({x, i});
	}
	mins.clear();
	mins.PB({-INF, SZ(v)});
	FORD(i, SZ(v), 0)
	{
		int x = v[i];
		while(mins.back().fi >= x) mins.pop_back();
		rt[i] = mins.back().se;
		mins.PB({x, i});
	}
	int res = 0;
	FOR(i, 0, SZ(v))
	{
		ckmax(res, v[i] * (rt[i] - lt[i] - 1));
	}
	// FOR(i, 0, SZ(v))
	// {
	// 	cerr << v[i] << ' ';
	// }
	// cerr << "gets " << res << endl;
	return res;
}
int check(int x)
{
	//largest rectangle with all values >= x
	int res = 0;
	FOR(i, 0, N)
	{
		rt[i][M] = 0;
		FORD(j, M, 0)
		{
			rt[i][j] = ((grid[i][j] >= x) ? 1 + rt[i][j + 1] : 0);
		}
	}
	// if (x == 2)
	// {
	// 	FOR(i, 0, N)
	// 	{
	// 		FOR(j, 0, M)
	// 		{
	// 			cerr << rt[i][j] << ' ';
	// 		}
	// 		cerr << endl;
	// 	}
	// }
	FOR(j, 0, M)
	{
		vi num;
		FOR(i, 0, N)
		{
			num.PB(rt[i][j]);
		}
		ckmax(res, calc(num));
	}
	return res;

}
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 >> K;
	FOR(i, 0, N)
	{
		FOR(j, 0, M)
		{
			cin >> grid[i][j];
		}
	}
	int lo = 0, hi = INF;
	while(hi > lo)
	{
		int mid = (hi + lo + 1) >> 1;
		if (check(mid) >= K) lo = mid;
		else hi = mid - 1;
	}
	int res = check(lo);
	cout << lo << ' ' << res << '\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: 100 / 100