#include <bits/stdc++.h>
using namespace std;
// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e18
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
// input
template<class T> void IN(T& x) {cin >> x;}
template<class H, class... T> void IN(H& h, T&... t) {IN(h); IN(t...); }
// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }
// dp
template<class T> bool ckmin(T&a, T&b) { bool bl = a > b; a = min(a,b); return bl;}
template<class T> bool ckmax(T&a, T&b) { bool bl = a < b; a = max(a,b); return bl;}
void program();
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
program();
}
//===================//
// begin program //
//===================//
// mod library
ll MOD=1e9+7;
inline ll mod(ll x_) {
return (x_)%MOD;
}
ll modpow(ll x_, ll N_) {
if(N_ == 0) return 1;
ll a = modpow(x_,N_/2);
a = (a*a)%MOD;
if(N_%2) a = (a*x_)%MOD;
return a;
}
ll inv(ll x_) {
return modpow(x_, MOD-2);
}
class mi {
public:
mi(ll v=0) {value = v;}
mi operator+ (ll rs) {return mod(value+rs);}
mi operator- (ll rs) {return mod(value-rs+MOD);}
mi operator* (ll rs) {return mod(value*rs);}
mi operator/ (ll rs) {return mod(value*inv(rs));}
mi& operator+=(ll rs) {*this = (*this)+rs; return *this;}
mi& operator-=(ll rs) {*this = (*this)-rs; return *this;}
mi& operator*=(ll rs) {*this = (*this)*rs; return *this;}
mi& operator/=(ll rs) {*this = (*this)/rs; return *this;}
operator ll&() {return value;}
ll value;
};
typedef vector<mi> vmi;
const int MX = 3001;
const int N = (1<<20);
int n, m;
mi dp[MX][MX];
void program() {
IN(n,m);
RE(i,MX) dp[0][i] = 1;
mi inv2 = mi(1)/mi(2);
REP(x,1,MX) RE(y,MX) {
dp[x][y] += dp[x-1][y]; // empty left collumn
if(y)
dp[x][y] += dp[x-1][y-1]*mi(y)*4ll; // place one tent
if(y>=1 && x>=2)
dp[x][y] += dp[x-2][y-1]*mi(y)*mi(x-1); // place two tents in same row
if(x>=1 && y>=2)
dp[x][y] += dp[x-1][y-2]*mi(y)*mi(y-1)*inv2; // place two tents in same collumn
}
OUTL((ll)((mi)dp[n][m])-1ll);
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
679 ms |
70836 KB |
Output is correct |
2 |
Correct |
676 ms |
70788 KB |
Output is correct |
3 |
Correct |
675 ms |
70852 KB |
Output is correct |
4 |
Correct |
675 ms |
70880 KB |
Output is correct |
5 |
Correct |
669 ms |
70792 KB |
Output is correct |
6 |
Correct |
668 ms |
70788 KB |
Output is correct |
7 |
Correct |
673 ms |
70704 KB |
Output is correct |
8 |
Correct |
671 ms |
70788 KB |
Output is correct |
9 |
Correct |
673 ms |
70796 KB |
Output is correct |
10 |
Correct |
672 ms |
70792 KB |
Output is correct |
11 |
Correct |
670 ms |
70804 KB |
Output is correct |
12 |
Correct |
666 ms |
70732 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
679 ms |
70836 KB |
Output is correct |
2 |
Correct |
676 ms |
70788 KB |
Output is correct |
3 |
Correct |
675 ms |
70852 KB |
Output is correct |
4 |
Correct |
675 ms |
70880 KB |
Output is correct |
5 |
Correct |
669 ms |
70792 KB |
Output is correct |
6 |
Correct |
668 ms |
70788 KB |
Output is correct |
7 |
Correct |
673 ms |
70704 KB |
Output is correct |
8 |
Correct |
671 ms |
70788 KB |
Output is correct |
9 |
Correct |
673 ms |
70796 KB |
Output is correct |
10 |
Correct |
672 ms |
70792 KB |
Output is correct |
11 |
Correct |
670 ms |
70804 KB |
Output is correct |
12 |
Correct |
666 ms |
70732 KB |
Output is correct |
13 |
Correct |
671 ms |
70844 KB |
Output is correct |
14 |
Correct |
674 ms |
70804 KB |
Output is correct |
15 |
Correct |
675 ms |
70852 KB |
Output is correct |
16 |
Correct |
678 ms |
70800 KB |
Output is correct |
17 |
Correct |
672 ms |
70752 KB |
Output is correct |
18 |
Correct |
672 ms |
70796 KB |
Output is correct |
19 |
Correct |
672 ms |
70796 KB |
Output is correct |
20 |
Correct |
674 ms |
70780 KB |
Output is correct |
21 |
Correct |
676 ms |
70800 KB |
Output is correct |
22 |
Correct |
673 ms |
70852 KB |
Output is correct |
23 |
Correct |
675 ms |
70800 KB |
Output is correct |
24 |
Correct |
670 ms |
70800 KB |
Output is correct |
25 |
Correct |
675 ms |
70796 KB |
Output is correct |
26 |
Correct |
673 ms |
70796 KB |
Output is correct |
27 |
Correct |
682 ms |
70796 KB |
Output is correct |