#![allow(unused_imports)] use std::cmp::*; use std::collections::*; use std::io::Write; use std::ops::Bound::*; #[allow(unused_macros)] macro_rules! debug { ($($e:expr),*) => { #[cfg(debug_assertions)] $({ let (e, mut err) = (stringify!($e), std::io::stderr()); writeln!(err, "{} = {:?}", e, $e).unwrap() })* }; } fn main() { let n = read::(); let a = read_vec::() .iter() .map(|&x| Modulo(x)) .collect::>(); let mut a_clone = a.clone(); a_clone.sort(); a_clone.dedup(); let mut compress_dict = HashMap::new(); for i in 0..a_clone.len() { compress_dict.insert(a_clone[i], i); } let mut from_left = vec![Modulo(0); n]; let mut from_left_count = vec![0i64; n]; let mut seg = SegTree::new(compress_dict.len(), Modulo(0), |a, b| a + b); let mut seg_count = SegTree::new(compress_dict.len(), 0, |a, b| a + b); for i in 0..n { let cur = compress_dict[&a[i]]; from_left[i] = seg.query(cur + 1, compress_dict.len()); let val = seg.query(cur, cur + 1); seg.update(cur, val + a[i]); from_left_count[i] = seg_count.query(cur + 1, compress_dict.len()); let val = seg_count.query(cur, cur + 1); seg_count.update(cur, val + 1); } let mut from_right = vec![Modulo(0); n]; let mut from_right_count = vec![0i64; n]; let mut seg = SegTree::new(compress_dict.len(), Modulo(0), |a, b| a + b); let mut seg_count = SegTree::new(compress_dict.len(), 0, |a, b| a + b); for i in (0..n).rev() { let cur = compress_dict[&a[i]]; from_right[i] = seg.query(0, cur); let val = seg.query(cur, cur + 1); seg.update(cur, val + a[i]); from_right_count[i] = seg_count.query(0, cur); let val = seg_count.query(cur, cur + 1); seg_count.update(cur, val + 1); } // debug!(from_left); // debug!(from_right); let mut ans = Modulo(0); for i in 0..n { ans += from_left[i] * from_right_count[i]; ans += from_right[i] * from_left_count[i]; ans += a[i] * from_right_count[i] * from_left_count[i]; } println!("{}", ans); } fn read() -> T { let mut s = String::new(); std::io::stdin().read_line(&mut s).ok(); s.trim().parse().ok().unwrap() } fn read_vec() -> Vec { read::() .split_whitespace() .map(|e| e.parse().ok().unwrap()) .collect() } #[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)] struct Modulo(i64); static mut MODULUS: i64 = 998244353; impl Modulo { fn set_modulus(m: i64) { unsafe { MODULUS = m; } } fn get_modulus() -> i64 { unsafe { MODULUS } } fn new(x: i64) -> Modulo { let m = Modulo::get_modulus(); if x < 0 { Modulo(x % m + m) } else if x < m { Modulo(x) } else { Modulo(x % m) } } fn pow(self, p: i64) -> Modulo { if p == 0 { Modulo(1) } else { let mut t = self.pow(p / 2); t *= t; if p & 1 == 1 { t *= self; } t } } fn inv(self) -> Modulo { self.pow(Modulo::get_modulus() - 2) } } impl std::fmt::Display for Modulo { fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result { self.0.fmt(f) } } impl std::ops::AddAssign for Modulo { fn add_assign(&mut self, other: Modulo) { let m = Modulo::get_modulus(); self.0 += other.0; if self.0 >= m { self.0 -= m; } } } impl std::ops::MulAssign for Modulo { fn mul_assign(&mut self, other: Modulo) { let m = Modulo::get_modulus(); self.0 *= other.0; self.0 %= m; } } impl std::ops::SubAssign for Modulo { fn sub_assign(&mut self, other: Modulo) { let m = Modulo::get_modulus(); self.0 += m - other.0; if self.0 >= m { self.0 -= m; } } } macro_rules! impl_modulo_ops { ($imp:ident, $method:ident, $assign_imp:ident, $assign_method:ident) => { impl<'a> std::ops::$assign_imp<&'a Modulo> for Modulo { fn $assign_method(&mut self, other: &'a Modulo) { std::ops::$assign_imp::$assign_method(self, *other); } } impl std::ops::$imp for Modulo { type Output = Modulo; fn $method(self, other: Modulo) -> Modulo { let mut x = self; std::ops::$assign_imp::$assign_method(&mut x, other); x } } impl<'a> std::ops::$imp for &'a Modulo { type Output = Modulo; fn $method(self, other: Modulo) -> Modulo { std::ops::$imp::$method(*self, other) } } impl<'a> std::ops::$imp<&'a Modulo> for Modulo { type Output = Modulo; fn $method(self, other: &'a Modulo) -> Modulo { std::ops::$imp::$method(self, *other) } } impl<'a, 'b> std::ops::$imp<&'b Modulo> for &'a Modulo { type Output = Modulo; fn $method(self, other: &'b Modulo) -> Modulo { std::ops::$imp::$method(*self, *other) } } impl std::ops::$assign_imp for Modulo { fn $assign_method(&mut self, other: i64) { std::ops::$assign_imp::$assign_method(self, Modulo::new(other)); } } impl<'a> std::ops::$assign_imp<&'a i64> for Modulo { fn $assign_method(&mut self, other: &'a i64) { std::ops::$assign_imp::$assign_method(self, *other); } } impl std::ops::$imp for Modulo { type Output = Modulo; fn $method(self, other: i64) -> Modulo { let mut x = self; std::ops::$assign_imp::$assign_method(&mut x, other); x } } impl<'a> std::ops::$imp<&'a i64> for Modulo { type Output = Modulo; fn $method(self, other: &'a i64) -> Modulo { std::ops::$imp::$method(self, *other) } } impl<'a> std::ops::$imp for &'a Modulo { type Output = Modulo; fn $method(self, other: i64) -> Modulo { std::ops::$imp::$method(*self, other) } } impl<'a, 'b> std::ops::$imp<&'b i64> for &'a Modulo { type Output = Modulo; fn $method(self, other: &'b i64) -> Modulo { std::ops::$imp::$method(*self, *other) } } }; } impl_modulo_ops!(Add, add, AddAssign, add_assign); impl_modulo_ops!(Mul, mul, MulAssign, mul_assign); impl_modulo_ops!(Sub, sub, SubAssign, sub_assign); use std::iter::Sum; impl Sum for Modulo { fn sum(iter: I) -> Self where I: Iterator, { iter.fold(Modulo(0), |a, b| a + b) } } impl<'a> Sum<&'a Modulo> for Modulo { fn sum(iter: I) -> Self where I: Iterator, { iter.fold(Modulo(0), |a, b| a + b) } } #[derive(Clone)] struct SegTree where F: Fn(T, T) -> T, T: std::clone::Clone + std::marker::Copy, { n: usize, dat: Vec, init: T, functor: F, } impl SegTree where F: Fn(T, T) -> T, T: std::clone::Clone + std::marker::Copy, { fn new(n: usize, init: T, f: F) -> SegTree { let mut m = 1; // For simplicity, we use 2 ** n sized SegTree. while m < n { m *= 2; } SegTree { n: m, dat: vec![init; 2 * m - 1], init: init, functor: f, } } // dat[k] = a; fn update(&mut self, k: usize, a: T) { let mut k = k; k += self.n - 1; self.dat[k] = a; while k > 0 { k = (k - 1) / 2; self.dat[k] = (self.functor)(self.dat[k * 2 + 1], self.dat[k * 2 + 2]); } } // [a, b) fn query(&self, a: usize, b: usize) -> T { self.query_inner(a, b, 0, 0, self.n) } fn query_inner(&self, a: usize, b: usize, k: usize, l: usize, r: usize) -> T { if r <= a || b <= l { return self.init; } if a <= l && r <= b { return self.dat[k]; } let vl = self.query_inner(a, b, k * 2 + 1, l, (l + r) / 2); let vr = self.query_inner(a, b, k * 2 + 2, (l + r) / 2, r); (self.functor)(vl, vr) } }