Submission #40412

#	Time	Username	Problem	Language	Result	Execution time	Memory
40412		RockyB	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	407 ms	181356 KiB

skyscraper

/// In The Name Of God

#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,sse3,sse4,popcnt,abm,mmx")

#include <bits/stdc++.h>

#define f first
#define s second

#define pb push_back
#define pp pop_back
#define mp make_pair

#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()

#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);

#define nl '\n'
#define ioi exit(0);

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

const int N = (int)100 + 7;
const int L = (int)1e3 + 7;
const int inf = (int)1e9 + 7;
const int mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;

const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1};
const int dy[] = {0, 1, 0, -1, 1, -1, 1, -1};

using namespace std;

int n, S;
int a[N];

int dp[2][2][N][N][L];
int calc(int at = 1, int curl = 0, int cnt = 0, int l = 0, int r = 0) {
	if (cnt < 0) return 0;
	/// add previous cost
	if (at > 1) { 
		curl += (l + r + 2 * cnt) * (a[at] - a[at - 1]);
	} 
	if (curl > S) return 0;
	if (at == n) {
		return cnt == 0 ? 1 : 0; 
	}
	if (~dp[l][r][at][cnt][curl]) return dp[l][r][at][cnt][curl];
	ll res = 0;
	///new component
	res += calc(at + 1, curl, cnt + 1, l, r);
	res %= mod;
	///add to left border
	res += calc(at + 1, curl, cnt, 1, r);
	res %= mod;
	///connect left border and some middle component
	res += calc(at + 1, curl, cnt - 1, 1, r) * (ll)cnt;
	res %= mod;
	///add to right border
	res += calc(at + 1, curl, cnt, l, 1);
	res %= mod;
	///connect right border and some middle component
	res += calc(at + 1, curl, cnt - 1, l, 1) * (ll)cnt;
	res %= mod;
	///connect with middle component
	res += calc(at + 1, curl, cnt, l, r) * (ll)cnt * 2;
	res %= mod;
	///connect two middle component
	res += calc(at + 1, curl, cnt - 1, l, r) * (ll)cnt * (cnt - 1);
	res %= mod;
	return dp[l][r][at][cnt][curl] = res;
}	
int main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
	#endif
	Kazakhstan
	cin >> n >> S;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
	}
	sort (a + 1, a + 1 + n);
	memset(dp, -1, sizeof(dp));
	cout << calc();
	ioi
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 80 / 80