Submission #1971517

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Source Code Expand

#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
#pragma GCC optimize ("-O3")
using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
//---------------------------------------------------------------------------------------------------
template<int MOD> struct ModInt {
    static const int Mod = MOD; unsigned x; ModInt() : x(0) { }
    ModInt(signed sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
    ModInt(signed long long sig) { x = sig < 0 ? sig % MOD + MOD : sig % MOD; }
    int get() const { return (int)x; }
    ModInt &operator+=(ModInt that) { if ((x += that.x) >= MOD) x -= MOD; return *this; }
    ModInt &operator-=(ModInt that) { if ((x += MOD - that.x) >= MOD) x -= MOD; return *this; }
    ModInt &operator*=(ModInt that) { x = (unsigned long long)x * that.x % MOD; return *this; }
    ModInt &operator/=(ModInt that) { return *this *= that.inverse(); }
    ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
    ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
    ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
    ModInt operator/(ModInt that) const { return ModInt(*this) /= that; }
    ModInt inverse() const { long long a = x, b = MOD, u = 1, v = 0;
        while (b) { long long t = a / b; a -= t * b; std::swap(a, b); u -= t * v; std::swap(u, v); }
        return ModInt(u); }
    bool operator==(ModInt that) const { return x == that.x; }
    bool operator!=(ModInt that) const { return x != that.x; }
    ModInt operator-() const { ModInt t; t.x = x == 0 ? 0 : Mod - x; return t; }
};
template<int MOD> ostream& operator<<(ostream& st, const ModInt<MOD> a) { st << a.get(); return st; };
template<int MOD> ModInt<MOD> operator^(ModInt<MOD> a, unsigned long long k) {
    ModInt<MOD> r = 1; while (k) { if (k & 1) r *= a; a *= a; k >>= 1; } return r; }
typedef ModInt<1000000007> mint;
/*---------------------------------------------------------------------------------------------------
　　　　　　　　　　　 ∧＿∧  
　　　　　 ∧＿∧ 　（´<_｀ ）　 Welcome to My Coding Space!
　　　　 （ ´_ゝ`）　/　 ⌒i     
　　　　／　　　＼　 　  |　|     
　　　 /　　 /￣￣￣￣/　　|  
　 ＿_(__ﾆつ/　    ＿/ .| .|＿＿＿＿  
　 　　　＼/＿＿＿＿/　（u　⊃  
---------------------------------------------------------------------------------------------------*/

// http://d.hatena.ne.jp/incognita/20110305/1299344781
// todo: 他の実装
// Q(i,j) := 整数iを順序を区別せずに「j個の自然数」の和に分ける場合の数
// R(i,j) := 整数iを順序を区別せずに「j個以下の自然数」の和に分ける場合の数
template<typename T> struct PartitionNumber{
    int n;
    vector<T> _P; vector<vector<T>> _PP, _Q, _R;
    PartitionNumber(int _n) {
        n = _n;
        _P.resize(n + 1);
        _PP.resize(n + 1, vector<T>(n + 1));
        _Q.resize(n + 1, vector<T>(n + 1));
        _R.resize(n + 1, vector<T>(n + 1));

        _Q[0][0] = 1;
        rep(i, 1, n + 1) rep(j, 1, n + 1) {
            _Q[i][j] += _Q[i - 1][j - 1];
            if (j <= i) _Q[i][j] += _Q[i - j][j];
        }
        rep(i, 0, n + 1) {
            _R[i][0] = _Q[i][0];
            rep(j, 1, n + 1) _R[i][j] = _R[i][j - 1] + _Q[i][j];
        }
    }

    mint R(int i, int j) {
        assert(0 <= j and 0 <= i and j <= n and i <= n);
        return _R[i][j];
    }
};
//---------------------------------------------------------------------------------------------------
PartitionNumber<mint> pn(1010);
mint solve(vector<int> &kill, vector<int>& death) {
    deque<pair<int, int>> cnt;
    cnt.push_back({ kill[0], 1 });
    rep(i, 1, kill.size()) {
        if (cnt.back().first == kill[i]) cnt.back().second++;
        else cnt.push_back({ kill[i], 1 });
    }

    int sm = 0;
    fore(i, death) sm += i;
    int n = cnt.size();

    vector<vector<mint>> dp(n + 1, vector<mint>(sm + 1, 0));
    dp[0][0] = 1;
    rep(g, 0, n) rep(s, 0, sm + 1) rep(i, 0, sm - s + 1) dp[g + 1][s + i] += dp[g][s] * pn.R(i, cnt[g].second);

    return dp[n][sm];
}
//---------------------------------------------------------------------------------------------------
void _main() {
    int N, M;
    cin >> N >> M;

    vector<int> A(N), B(M);
    rep(i, 0, N) cin >> A[i];
    rep(i, 0, M) cin >> B[i];

    mint a = solve(A, B);
    mint b = solve(B, A);
    mint ans = a * b;
    cout << ans << endl;
}

Submission Info

Judge Result