#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using ll = long long; using namespace atcoder; const long long BASE_NUM = 1000000007; // https://scrapbox.io/pocala-kyopro/%E6%8B%A1%E5%BC%B5%E3%83%A6%E3%83%BC%E3%82%AF%E3%83%AA%E3%83%83%E3%83%89%E3%81%AE%E4%BA%92%E9%99%A4%E6%B3%95 // https://ei1333.github.io/luzhiled/snippets/math/combination.html template struct ModInt { int x; ModInt() : x(0) {} ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} ModInt &operator+=(const ModInt &p) { if ((x += p.x) >= mod) x -= mod; return *this; } ModInt &operator-=(const ModInt &p) { if ((x += mod - p.x) >= mod) x -= mod; return *this; } ModInt &operator*=(const ModInt &p) { x = (int)(1LL * x * p.x % mod); return *this; } ModInt &operator/=(const ModInt &p) { *this *= p.inverse(); return *this; } ModInt operator-() const { return ModInt(-x); } ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; } ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; } ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; } ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; } bool operator==(const ModInt &p) const { return x == p.x; } bool operator!=(const ModInt &p) const { return x != p.x; } ModInt inverse() const { int a = x, b = mod, u = 1, v = 0, t; while (b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } return ModInt(u); } ModInt pow(int64_t n) const { ModInt ret(1), mul(x); while (n > 0) { if (n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; } friend istream &operator>>(istream &is, ModInt &a) { int64_t t; is >> t; a = ModInt(t); return (is); } static int get_mod() { return mod; } }; using modint = ModInt; template struct Combination { vector _fact, _rfact, _inv; Combination(int sz) : _fact(sz + 1), _rfact(sz + 1), _inv(sz + 1) { _fact[0] = _rfact[sz] = _inv[0] = 1; for (int i = 1; i <= sz; i++) _fact[i] = _fact[i - 1] * i; _rfact[sz] /= _fact[sz]; for (int i = sz - 1; i >= 0; i--) _rfact[i] = _rfact[i + 1] * (i + 1); for (int i = 1; i <= sz; i++) _inv[i] = _rfact[i] * _fact[i - 1]; } inline T fact(int k) const { return _fact[k]; } inline T rfact(int k) const { return _rfact[k]; } inline T inv(int k) const { return _inv[k]; } T P(int n, int r) const { if (r < 0 || n < r) return 0; return fact(n) * rfact(n - r); } T C(int p, int q) const { if (q < 0 || p < q) return 0; return fact(p) * rfact(q) * rfact(p - q); } T H(int n, int r) const { if (n < 0 || r < 0) return (0); return r == 0 ? 1 : C(n + r - 1, r); } }; using modint = ModInt; //zero indexed and vector template< typename T> class BIT { public: vector data; BIT(long long n) : data(n) {} // indexに足す void add(int index, T v) { int N = data.size(); for (int i = index; i < N; i |= i + 1) { data[i] += v; } } // [0,index)の和 T sum(int index) { T retValue = 0; for (int i = index - 1; i >= 0; i = (i & (i + 1)) - 1) { retValue += data[i]; } return retValue; } // [l,r)の和 T sum(int l,int r) { return sum(r) - sum(l); } void show(){ for (auto v:data){ cout << v << endl; } } }; int solve() { ll N; cin >> N; vector P(N); vector revP(N); for(int i = 0;i < N;i++){ cin >> P[i]; P[i]--; revP[P[i]] = i; } modint two = 2; BIT bitPower(N); BIT bitOne(N); modint ans = 0; for(int i = 0;i < N;i++){ ll index = revP[i]; // cout << i << ":" << two.pow(N-1)*bitOne.sum(index,N) - bitPower.sum(index,N)*two.pow(index) << endl; ans += two.pow(N-1)*bitOne.sum(index,N) - bitPower.sum(index,N)*two.pow(index); bitPower.add(index,two.pow(N-1-index)); bitOne.add(index,1); } cout << ans << endl; return 0; } int main() { // ll T; // cin >> T; // while (T--) // { solve(); // } cout << flush; return 0; }