Submission #98293

# Submission time Handle Problem Language Result Execution time Memory
98293 2019-02-21T22:17:57 Z qkxwsm Skyscraper (JOI16_skyscraper) C++14
20 / 100
2000 ms 180728 KB
#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, int> dp[MAXN][2][2][MAXN];
int ans;
int states = 0;

int solve(int idx, bool lt, bool rt, int cc, int sum)
{
	states++;
	if (idx == N)
	{
		// if (sum <= L && lt == 1 && rt == 1 && cc == 1) DBG(sum);
		return ((sum <= L && lt == 1 && rt == 1 && cc == 1) ? 1 : 0);
	}
	if (dp[idx][lt][rt][cc].find(sum) != dp[idx][lt][rt][cc].end())
	{
		return dp[idx][lt][rt][cc][sum];
	}
	ll res = 0;
	if (!lt)
	{
		//latch onto the left!
		res += solve(idx + 1, 1, rt, cc, sum + arr[idx]);
		//create a new one on the left!
		res += solve(idx + 1, 1, rt, cc + 1, sum - arr[idx]);
	}
	if (!rt)
	{
		//latch onto the right!
		res += solve(idx + 1, lt, 1, cc, sum + arr[idx]);
		//create a new one on the right!
		res += solve(idx + 1, lt, 1, cc + 1, sum - arr[idx]);
	}
	//create a new connected component that's by itself!
	res += 1ll * (cc + 1 - lt - rt) * solve(idx + 1, lt, rt, cc + 1, sum - 2 * arr[idx]);
	//join two connected components!
	if (cc > 1) res += 1ll * (cc - 1) * solve(idx + 1, lt, rt, cc - 1, sum + 2 * arr[idx]);
	//latch on right!
	res += 1ll * (cc - rt) * solve(idx + 1, lt, rt, cc, sum);
	//latch on left!
	res += 1ll * (cc - lt) * solve(idx + 1, lt, rt, cc, sum);
	res %= INF;
	dp[idx][lt][rt][cc][sum] = res;
	// cerr << idx << ' ' << lt << ' ' << rt << ' ' << cc << ' ' << sum << ' ' << res << endl;
	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 >> 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;
	}
	ans = solve(1, 0, 0, 1, -2 * arr[0]); nmod(ans, INF);
	ans += solve(1, 1, 0, 1, -arr[0]); nmod(ans, INF);
	ans += solve(1, 0, 1, 1, -arr[0]); nmod(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
*/
# Verdict Execution time Memory Grader output
1 Correct 16 ms 11136 KB Output is correct
2 Correct 17 ms 11136 KB Output is correct
3 Correct 22 ms 11128 KB Output is correct
4 Correct 21 ms 11256 KB Output is correct
5 Correct 20 ms 11520 KB Output is correct
6 Correct 21 ms 11520 KB Output is correct
7 Correct 18 ms 11136 KB Output is correct
8 Correct 22 ms 11264 KB Output is correct
9 Correct 24 ms 11520 KB Output is correct
10 Correct 16 ms 11264 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 22 ms 11512 KB Output is correct
2 Correct 42 ms 13796 KB Output is correct
3 Correct 19 ms 11684 KB Output is correct
4 Correct 32 ms 13820 KB Output is correct
5 Correct 48 ms 14328 KB Output is correct
6 Correct 29 ms 12920 KB Output is correct
7 Correct 23 ms 12152 KB Output is correct
8 Correct 24 ms 11648 KB Output is correct
9 Correct 24 ms 11748 KB Output is correct
10 Correct 33 ms 13148 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 16 ms 11136 KB Output is correct
2 Correct 17 ms 11136 KB Output is correct
3 Correct 22 ms 11128 KB Output is correct
4 Correct 21 ms 11256 KB Output is correct
5 Correct 20 ms 11520 KB Output is correct
6 Correct 21 ms 11520 KB Output is correct
7 Correct 18 ms 11136 KB Output is correct
8 Correct 22 ms 11264 KB Output is correct
9 Correct 24 ms 11520 KB Output is correct
10 Correct 16 ms 11264 KB Output is correct
11 Correct 22 ms 11512 KB Output is correct
12 Correct 42 ms 13796 KB Output is correct
13 Correct 19 ms 11684 KB Output is correct
14 Correct 32 ms 13820 KB Output is correct
15 Correct 48 ms 14328 KB Output is correct
16 Correct 29 ms 12920 KB Output is correct
17 Correct 23 ms 12152 KB Output is correct
18 Correct 24 ms 11648 KB Output is correct
19 Correct 24 ms 11748 KB Output is correct
20 Correct 33 ms 13148 KB Output is correct
21 Correct 434 ms 45192 KB Output is correct
22 Execution timed out 2076 ms 180728 KB Time limit exceeded
23 Halted 0 ms 0 KB -