Submission #98295

#TimeUsernameProblemLanguageResultExecution timeMemory
98295qkxwsmSkyscraper (JOI16_skyscraper)C++14
20 / 100
1495 ms525312 KiB
#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 113

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, L;
int arr[MAXN];
hash_table<int, ll> dp[MAXN][2][2][MAXN];
ll ans;

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 >> L;
	if (N == 1)
	{
		cout << "1\n";
		return 0;
	}
	FOR(i, 0, N)
	{
		cin >> arr[i];
	}
	sort(arr, arr + N);
	if (arr[N - 1] - arr[0] > L)
	{
		cout << "0\n";
		return 0;
	}
	FOR(i, 0, L + 1)
	{
		dp[N - 1][1][1][1][i] = 1;
	}
	FORD(i, N, 1)
	{
		FOR(j, 0, 2)
		{
			FOR(k, 0, 2)
			{
				FOR(m, 1, N + 1)
				{
					for (auto x : dp[i][j][k][m])
					{
						int n = x.fi;
						ll val = x.se % INF; if (val == 0) continue;
						if (j)
						{
							//latch onto the left!
							dp[i - 1][0][k][m][n - arr[i]] += val;
							//new guy on the left!
							dp[i - 1][0][k][m - 1][n + arr[i]] += val;
						}
						if (k)
						{
							//latch onto the right!
							dp[i - 1][j][0][m][n - arr[i]] += val;
							//new guy on the right!
							dp[i - 1][j][0][m - 1][n + arr[i]] += val;
						}
						//new cc by itself
						dp[i - 1][j][k][m - 1][n + 2 * arr[i]] += val * (m - j - k);
						//join two cc
						dp[i - 1][j][k][m + 1][n - 2 * arr[i]] += val * (m);
						//latch on left, right
						dp[i - 1][j][k][m][n] += val * (2 * m - j - k);
					}
				}
			}
		}
	}
	ans += dp[0][0][0][1][-2 * arr[0]];
	ans += dp[0][1][0][1][-arr[0]];
	ans += dp[0][0][1][1][-arr[0]];
	ans %= INF;
	cout << ans << '\n';
	//when we place a # down, we can either say: ok new left spot open! ok new right spot open! ok new nothing open!
	//dp of:
	//total sum,
	// 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
*/
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