Submission #130013

#	Time	Username	Problem	Language	Result	Execution time	Memory
130013		qkxwsm	Cake 3 (JOI19_cake3)	C++14	24 / 100	4010 ms	22852 KiB

cake3

#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 200013

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;
pll arr[MAXN];
ll ans = -LLINF;
ll sum = 0;
ordered_set<pll> ord;
multiset<ll> negative;
pii stor;

void ins(ll x)
{
	//if this will become among the top k, subtract kth and add this
	if (negative.find(x) != negative.end())
	{
		negative.erase(negative.find(x));
		return;
	}
	auto p = *ord.find_by_order(SZ(ord) - (M - 2));
	if (p.fi <= x)
	{
		sum -= p.fi;
		sum += x;
	}
	ord.insert({x, randomize(LLINF)});
}
void del(ll x)
{
	//if this is currently among the top k, subtract this and add the kth
	auto pp = ord.UB({x, -LLINF});
	if (pp -> fi != x)
	{
		negative.insert(x);
		return;
	}
	ord.erase(pp);
	auto p = *ord.find_by_order(SZ(ord) - (M - 2));
	if (p.fi <= x)
	{
		sum -= x;
		sum += p.fi;
	}
}
void move(pii p)
{
	while(stor.se < p.se)
	{
		stor.se++;
		ins(arr[stor.se - 1].se);
	}
	while(stor.se > p.se)
	{
		del(arr[stor.se - 1].se);
		stor.se--;
	}
	while(stor.fi < p.fi)
	{
		del(arr[stor.fi - 1].se);
		stor.fi++;
	}
	while(stor.fi > p.fi)
	{
		stor.fi--;
		ins(arr[stor.fi - 1].se);
	}
}

void solve(int L, int R, int optl, int optr)
{
	//it must start off containing L + 1..optl - 1
	if (L > R) return;
	int mid = (L + R) >> 1;
	ll best = -LLINF; int opt = -1;
	FOR(i, optl, optr + 1)
	{
		// cerr << "INS " << i - 1 << endl;
		move({mid + 2, i});
		if (i - mid + 1 >= M)
		{
			ll cur = arr[mid].se + 2 * arr[mid].fi + arr[i].se - 2 * arr[i].fi + sum;
			if (cur > best)
			{
				best = cur;
				opt = i;
			}
		}
	}
	ckmax(ans, best);
	solve(L, mid - 1, optl, opt);
	solve(mid + 1, R, opt, optr);
	//it must end off containing R...whatever
}

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)
	{
		cin >> arr[i].se >> arr[i].fi;
	}
	sort(arr, arr + N);
	// FOR(i, 0, N)
	// {
	// 	cerr << arr[i].fi << ' ' << arr[i].se << endl;
	// }
	FOR(i, 0, M)
	{
		ord.insert({-LARGE, randomize(LLINF)});
	}
	sum = (-LARGE) * (M - 2);
	stor = {2, 1};
	solve(0, N - M, M - 1, N - 1);
	cout << ans << '\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: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 0 / 76