Submission #509562

#	Time	Username	Problem	Language	Result	Execution time	Memory
509562		NhatMinh0208	NoM (RMI21_nom)	C++14	100 / 100	40 ms	668 KiB

Main

#ifndef CPL_TEMPLATE
#define CPL_TEMPLATE
/*
	Normie's Template v2.5
	Changes:
    Added warning against using pragmas on USACO.
*/
// Standard library in one include.
#include <bits/stdc++.h>
using namespace std;
 
// ordered_set library.
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set(el) tree<el,null_type,less<el>,rb_tree_tag,tree_order_statistics_node_update>
 
// AtCoder library. (Comment out these two lines if you're not submitting in AtCoder.) (Or if you want to use it in other judges, run expander.py first.)
//#include <atcoder/all>
//using namespace atcoder;

//Pragmas (Comment out these three lines if you're submitting in szkopul or USACO.)
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast,unroll-loops,tree-vectorize")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
 
//File I/O.
#define FILE_IN "cseq.inp"
#define FILE_OUT "cseq.out"
#define ofile freopen(FILE_IN,"r",stdin);freopen(FILE_OUT,"w",stdout)
 
//Fast I/O.
#define fio ios::sync_with_stdio(0);cin.tie(0)
#define nfio cin.tie(0)
#define endl "\n"
 
//Order checking.
#define ord(a,b,c) ((a>=b)and(b>=c))
 
//min/max redefines, so i dont have to resolve annoying compile errors.
#define min(a,b) (((a)<(b))?(a):(b))
#define max(a,b) (((a)>(b))?(a):(b))

// Fast min/max assigns to use with AVX.
// Requires g++ 9.2.0.
template<typename T>
__attribute__((always_inline)) void chkmin(T& a, const T& b) {
    a=(a<b)?a:b;
}

template<typename T>
__attribute__((always_inline)) void chkmax(T& a, const T& b) {
    a=(a>b)?a:b;
}
 
//Constants.
#define MOD (ll(1000000007))
#define MAX 300001
#define mag 320
const long double PI=3.14159265358979;
 
//Pairs and 3-pairs.
#define p1 first
#define p2 second.first
#define p3 second.second
#define fi first
#define se second
#define pii(element_type) pair<element_type,element_type>
#define piii(element_type) pair<element_type,pii(element_type)>
 
//Quick power of 2.
#define pow2(x) (ll(1)<<x)
 
//Short for-loops.
#define ff(i,__,___) for(int i=__;i<=___;i++)
#define rr(i,__,___) for(int i=__;i>=___;i--)
 
//Typedefs.
#define bi BigInt
typedef long long ll;
typedef long double ld;
typedef short sh;

// Binpow and stuff
ll BOW(ll a, ll x, ll p)
{
	if (!x) return 1;
	ll res=BOW(a,x/2,p);
	res*=res;
	res%=p;
	if (x%2) res*=a;
	return res%p;
}
ll INV(ll a, ll p)
{
	return BOW(a,p-2,p);
}
//---------END-------//
#endif
ll n,m,i,j,k,t,t1,u,v,a,b,res,factor;
vector<ll> gr[4001],va,vb;
ll cnt[4001];
ll fac[4001];
ll inv[4001];
int main()
{
	fio;
	cin>>n>>m;
	for (i=1;i<=2*n;i++) cnt[i%m]++;
	fac[0]=inv[0]=1;
	for (i=1;i<=2*n;i++) {
		fac[i]=(fac[i-1]*i)%MOD;
		inv[i]=INV(fac[i],MOD);
	}
	for (i=0;i<m;i++) {
		for (j=0;j<=cnt[i]/2;j++) {
			gr[i].push_back(inv[j]*inv[cnt[i]-2*j]%MOD);
		}
	}
	t=0;
	va.push_back(1);
	factor=1;
	for (i=0;i<m;i++) {
		vb.clear();
		for (j=0;j<=cnt[i]/2+t;j++) vb.push_back(0);
		for (j=0;j<=t;j++) for (k=0;k<=cnt[i]/2;k++) {
			vb[j+k]+=va[j]*gr[i][k];
			vb[j+k]%=MOD;
		}
		va=vb;
		t+=cnt[i]/2;
		factor*=fac[cnt[i]];
		factor%=MOD;
	}
	for (i=0;i<=t;i++) {
		u=va[i]*factor%MOD;
		u*=fac[i]; u%=MOD;
		u*=fac[2*n-2*i]; u%=MOD;
		u*=fac[n]; u%=MOD;
		u*=inv[i]; u%=MOD;
		u*=inv[n-i]; u%=MOD;
		if (i&1) {
			res+=MOD-u;
		}
		else {
			res+=u;
		}
	}
	cout<<res%MOD;
}

Compilation message (stderr)

Main.cpp:23: warning: ignoring '#pragma comment ' [-Wunknown-pragmas]
   23 | #pragma comment(linker, "/stack:200000000")
      |

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 13 / 13
• Subtask 4: 18 / 18
• Subtask 5: 48 / 48