#include #include using namespace std; typedef unsigned long long _ulong; typedef long long int lint; typedef pair plint; typedef pair pld; #define ALL(x) (x).begin(), (x).end() #define SZ(x) ((lint)(x).size()) #define FOR(i, begin, end) for(lint i=(begin),i##_end_=(end);i=i##_begin_;i--) #define REP(i, n) FOR(i,0,n) #define IREP(i, n) IFOR(i,0,n) #define endk '\n' template auto add = [](T a, T b) -> T { return a + b; }; template auto f_max = [](T a, T b) -> T { return max(a, b); }; template auto f_min = [](T a, T b) -> T { return min(a, b); }; template using V = vector; using Vl = V; using VVl = V; template< typename T > ostream& operator<<(ostream & os, const vector< T > & v) { for (int i = 0; i < (int)v.size(); i++) os << v[i] << (i + 1 != v.size() ? " " : ""); return os; } template< typename T >istream& operator>>(istream & is, vector< T > & v) { for (T& in : v) is >> in; return is; } template bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; } template bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; } lint gcd(lint a, lint b) { if (b == 0) return a; else return gcd(b, a % b); } lint ceil(lint a, lint b) { return (a + b - 1) / b; } lint digit(lint a) { return (lint)log10(a); } lint dist(plint a, plint b) { return abs(a.first - b.first) * abs(a.first - b.first) + abs(a.second - b.second) * abs(a.second - b.second); } void Worshall_Floyd(VVl& g) { REP(k, SZ(g)) REP(i, SZ(g)) REP(j, SZ(g)) chmin(g[i][j], g[i][k] + g[k][j]); } const lint MOD = 1e9 + 7, INF = 5e18; lint dx[8] = { 1, 0, -1, 0, 1, -1, 1, -1 }, dy[8] = { 0, 1, 0, -1, -1, -1, 1, 1 }; void YN(bool flag) { cout << (flag ? "YES" : "NO") << endk; } void yn(bool flag) { cout << (flag ? "Yes" : "No") << endk; } typedef pair Pa; typedef pair tlint; struct Edge { lint from, to; lint cost; Edge(lint u, lint v, lint c) { cost = c; from = u; to = v; } bool operator<(const Edge& e) const { return cost < e.cost; } }; struct WeightedEdge { lint to; lint cost; WeightedEdge(lint v, lint c = 1) { to = v; cost = c; } bool operator<(const WeightedEdge& e) const { return cost < e.cost; } }; using WeightedGraph = V>; template class modint { using u64 = std::int_fast64_t; public: u64 a; constexpr modint(const u64 x = 0) noexcept : a(x% Modulus) {} constexpr u64& value() noexcept { return a; } constexpr const u64& value() const noexcept { return a; } constexpr modint operator+(const modint rhs) const noexcept { return modint(*this) += rhs; } constexpr modint operator-(const modint rhs) const noexcept { return modint(*this) -= rhs; } constexpr modint operator*(const modint rhs) const noexcept { return modint(*this) *= rhs; } constexpr modint operator/(const modint rhs) const noexcept { return modint(*this) /= rhs; } constexpr modint& operator+=(const modint rhs) noexcept { a += rhs.a; if (a >= Modulus) { a -= Modulus; } return *this; } constexpr modint& operator-=(const modint rhs) noexcept { if (a < rhs.a) { a += Modulus; } a -= rhs.a; return *this; } constexpr modint& operator*=(const modint rhs) noexcept { a = a * rhs.a % Modulus; return *this; } constexpr modint& operator/=(modint rhs) noexcept { u64 exp = Modulus - 2; while (exp) { if (exp % 2) { *this *= rhs; } rhs *= rhs; exp /= 2; } return *this; } }; typedef modint ModInt; ModInt mod_pow(ModInt x, lint n) { ModInt ret = 1; while (n > 0) { if (n & 1) (ret *= x); (x *= x); n >>= 1; } return ret; } ModInt func[200000]; void funcinit(int N) { func[0] = 1; for (int i = 1; i <= N; i++) { func[i] = func[i - 1] * i; } } ModInt comb(ModInt n, ModInt r) { if (n.a <= 0 || n.a < r.a) { return 1; } return func[n.a] / (func[r.a] * func[(n - r).a]); } struct BinaryIndexedTree { int n; vector bit; BinaryIndexedTree(int n_) : n(n_ + 1), bit(n, 0) {} void add(int i, lint x) { for (int idx = i; idx < n; idx += (idx & -idx)) { bit[idx] += x; } } lint sum(int i) { lint s = 0; for (int idx = i; idx > 0; idx -= (idx & -idx)) { s += bit[idx]; } return s; } int lower_bound(lint w) { if (w <= 0) { return 0; } else { int x = 0, r = 1; while (r < n) r = r << 1; for (int len = r; len > 0; len = len >> 1) { if (x + len < n && bit[x + len] < w) { w -= bit[x + len]; x += len; } } return x; } } void show() { for (int i = 0; i < n - 1; i++) { cout << sum(i) - sum(i - 1) << " "; } cout << endk; } }; struct ExtendBinaryIndexedTree { public: ExtendBinaryIndexedTree(int _n) { init(_n); } //半開区間[l, r) void add(int l, int r, lint x) { add_sub(0, l, -x * (l - 1)); add_sub(0, r, x * (r - 1)); add_sub(1, l, x); add_sub(1, r, -x); } //区間[0, i) lint sum(int i) { return sum_sub(0, i) + sum_sub(1, i) * i; } void show() { for (int i = 0; i < n - 1; i++) { cout << sum(i + 1) - sum(i) << " "; } cout << endk; } private: int n; vector bit[2]; void init(int _n) { n = _n + 1; bit[0].assign(n, 0); bit[1].assign(n, 0); } void add_sub(int p, int i, lint x) { for (int idx = i; idx < n; idx += (idx & -idx)) { bit[p][idx] += x; } } lint sum_sub(int p, int i) { lint s = 0; for (int idx = i; idx > 0; idx -= (idx & -idx)) { s += bit[p][idx]; } return s; } }; lint N; int main() { cin.tie(0); ios_base::sync_with_stdio(false); cin >> N; vector arr(N); set st; REP(i, N) { cin >> arr[i]; st.insert(arr[i]); } vector vec; vec.push_back(0); for (lint v : st) vec.push_back(v); map fx; for (int i = 0; i < SZ(vec); i++) { fx[vec[i]] = i; } REP(i, N) { arr[i] = fx[arr[i]]; } BinaryIndexedTree upper_sum(SZ(vec)), lower_sum(SZ(vec)); BinaryIndexedTree upper_tree(SZ(vec)), lower_tree(SZ(vec)); REP(i, N) { lower_sum.add(arr[i], vec[arr[i]]); lower_tree.add(arr[i], 1); } ModInt ans = 0; REP(i, N) { lower_sum.add(arr[i], -vec[arr[i]]); lower_tree.add(arr[i], -1); ModInt l = lower_tree.sum(arr[i] - 1), u = upper_tree.sum(SZ(vec)) - upper_tree.sum(arr[i]); ans += u * lower_sum.sum(arr[i] - 1); ans += u * l * vec[arr[i]]; ans += l * (upper_sum.sum(SZ(vec)) - upper_sum.sum(arr[i])); upper_sum.add(arr[i], vec[arr[i]]); upper_tree.add(arr[i], 1); } cout << ans.a << endk; }