Submission #381321

#	Time	Username	Problem	Language	Result	Execution time	Memory
381321		CSQ31	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	426 ms	320236 KiB

skyscraper

#pragma GCC optimize("Ofast") 
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
#define all(a) a.begin(),a.end()
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define MOD (ll)(1e9+7)
#define INF (ll)(1e18)
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
typedef pair<int,pii> P;
ll gcd(ll a,ll b){if(!b)return a;else return gcd(b,a%b);}
ll dp[101][101][1001][2][2];
ll n,L;
vector<ll>a;
//go in reverse direction,treat dp states like a tree
// 0,0,0,0,0 is the root
ll solve(int i,int comp,int cur,int l,int r){
	
	int ncur = cur;
	if(i)ncur+=(2*comp + l + r) * (a[i]-a[i-1]);
	if(ncur>L)return 0;
	if(comp < 0)return 0;
	if(dp[i][comp][cur][l][r] != -1)return dp[i][comp][cur][l][r];
	if(i == n-1)return comp==0?1:0;
	ll res = 0;
	res+=solve(i+1,comp,ncur,1,r);
	res+=solve(i+1,comp-1,ncur,1,r) * comp;
	
	res+=solve(i+1,comp,ncur,l,1);
	res+=solve(i+1,comp-1,ncur,l,1) * comp;
	
	res+=solve(i+1,comp+1,ncur,l,r);
	res+=solve(i+1,comp,ncur,l,r) * comp * 2;
	res+=solve(i+1,comp-1,ncur,l,r) * (comp)*(comp-1);
	
	return dp[i][comp][cur][l][r] = res%MOD;
}
int main()
{
	cin>>n>>L;
	a.resize(n);
	for(int i=0;i<n;i++)cin>>a[i];
	sort(all(a));
	memset(dp,-1,sizeof(dp));
	cout<< solve(0,0,0,0,0);
	
}

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