Language: C++

/*------------------------------------------------------------------*/
/*------------------------- begin template -------------------------*/
/*------------------------------------------------------------------*/

// ref: tanakh <https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8>
// diff: using Parser
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut parser = Parser::from_str($s);
        input_inner!{parser, $($r)*}
    };
    (parser = $parser:ident, $($r:tt)*) => {
        input_inner!{$parser, $($r)*}
    };
    (new_stdin_parser = $parser:ident, $($r:tt)*) => {
        let stdin = std::io::stdin();
        let reader = std::io::BufReader::new(stdin.lock());
        let mut $parser = Parser::new(reader);
        input_inner!{$parser, $($r)*}
    };
    ($($r:tt)*) => {
        input!{new_stdin_parser = parser, $($r)*}
    };
}

macro_rules! input_inner {
    ($parser:ident) => {};
    ($parser:ident, ) => {};
    ($parser:ident, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($parser, $t);
        input_inner!{$parser $($r)*}
    };
}

macro_rules! read_value {
    ($parser:ident, ( $($t:tt),* )) => {
        ( $(read_value!($parser, $t)),* )
    };
    ($parser:ident, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($parser, $t)).collect::<Vec<_>>()
    };
    ($parser:ident, chars) => {
        read_value!($parser, String).chars().collect::<Vec<char>>()
    };
    ($parser:ident, usize1) => {
        read_value!($parser, usize) - 1
    };
    ($parser:ident, $t:ty) => {
        $parser.next::<$t>().expect("Parse error")
    };
}

use std::io;
use std::io::BufRead;
use std::str;

// ref: tatsuya6502 <https://qiita.com/tatsuya6502/items/cd448486f7ef7b5b8c7e>
// ref: wariuni <https://qiita.com/tatsuya6502/items/cd448486f7ef7b5b8c7e#comment-7040a5ae96305e884eb9>
// diff: using std::io::BufRead::fill_buf()
pub struct Parser<R> {
    pub reader: R,
    buf: Vec<u8>,
    pos: usize,
}

impl Parser<io::Empty> {
    pub fn from_str(s: &str) -> Parser<io::Empty> {
        Parser {
            reader: io::empty(),
            buf: s.as_bytes().to_vec(),
            pos: 0,
        }
    }
}

impl<R: BufRead> Parser<R> {
    pub fn new(reader: R) -> Parser<R> {
        Parser {
            reader: reader,
            buf: vec![],
            pos: 0,
        }
    }
    pub fn update_buf(&mut self) {
        self.buf.clear();
        self.pos = 0;
        loop {
            let (len, complete) = {
                let buf2 = self.reader.fill_buf().unwrap();
                self.buf.extend_from_slice(buf2);
                let len = buf2.len();
                (len, buf2[len - 1] <= 0x20)
            };
            self.reader.consume(len);
            if complete {
                break;
            }
        }
    }
    pub fn next<T: str::FromStr>(&mut self) -> Result<T, T::Err> {
        loop {
            let mut begin = self.pos;
            while begin < self.buf.len() && (self.buf[begin] <= 0x20) {
                begin += 1;
            }
            let mut end = begin;
            while end < self.buf.len() && (self.buf[end] > 0x20) {
                end += 1;
            }
            if begin != self.buf.len() {
                self.pos = end;
                return unsafe { str::from_utf8_unchecked(&self.buf[begin..end]) }.parse::<T>();
            } else {
                self.update_buf();
            }
        }
    }
}

#[allow(unused_imports)]
use std::cmp::*;
use std::marker::PhantomData;
use std::ops::*;

pub trait ModP {
    fn as_u64() -> u64;
}

#[allow(non_camel_case_types)]
#[derive(Clone, Copy, Debug)]
pub struct Mod_1_000_000_007();
impl ModP for Mod_1_000_000_007 {
    fn as_u64() -> u64 {
        1_000_000_007
    }
}

#[allow(non_camel_case_types)]
#[derive(Clone, Copy, Debug)]
pub struct Mod_998_244_353();
impl ModP for Mod_998_244_353 {
    fn as_u64() -> u64 {
        998_244_353
    }
}

#[derive(Clone, Copy, PartialEq, Debug)]
pub struct Modular<P: ModP + Copy>(u64, PhantomData<P>);

impl<P: ModP + Copy> Modular<P> {
    pub fn new(x: u64) -> Modular<P> {
        Modular(x % P::as_u64(), PhantomData)
    }
    pub fn pow(self, n: u64) -> Modular<P> {
        if n == 0 {
            return Modular(1, PhantomData);
        }
        let t = self.pow(n / 2);
        if n % 2 == 0 {
            t * t
        } else {
            t * t * self
        }
    }
    pub fn as_u64(self) -> u64 {
        self.0
    }
}

impl<P: ModP + Copy> Add for Modular<P> {
    type Output = Self;
    fn add(self, rhs: Self) -> Self::Output {
        Modular((self.0 + rhs.0) % P::as_u64(), PhantomData)
    }
}

impl<P: ModP + Copy> AddAssign for Modular<P> {
    fn add_assign(&mut self, rhs: Self) {
        *self = *self + rhs;
    }
}

impl<P: ModP + Copy> Sub for Modular<P> {
    type Output = Self;
    fn sub(self, rhs: Self) -> Self::Output {
        Modular(
            (self.0 + P::as_u64() - rhs.0 % P::as_u64()) % P::as_u64(),
            PhantomData,
        )
    }
}

impl<P: ModP + Copy> SubAssign for Modular<P> {
    fn sub_assign(&mut self, rhs: Self) {
        *self = *self - rhs;
    }
}

impl<P: ModP + Copy> Neg for Modular<P> {
    type Output = Modular<P>;
    fn neg(self) -> Modular<P> {
        Modular(P::as_u64() - self.0, PhantomData)
    }
}

impl<P: ModP + Copy> Mul for Modular<P> {
    type Output = Self;
    fn mul(self, rhs: Self) -> Self::Output {
        Modular(
            (self.0 % P::as_u64()) * (rhs.0 % P::as_u64()) % P::as_u64(),
            PhantomData,
        )
    }
}

impl<P: ModP + Copy> MulAssign for Modular<P> {
    fn mul_assign(&mut self, rhs: Self) {
        *self = *self * rhs;
    }
}

impl<P: ModP + Copy> Div for Modular<P> {
    type Output = Self;
    fn div(self, rhs: Self) -> Self::Output {
        if rhs.0 == 0 {
            loop {}
        }
        assert!(rhs.0 != 0);
        self * rhs.pow(P::as_u64() - 2)
    }
}

pub fn gen_fact_table<P: ModP + Copy>(n: usize) -> Vec<Modular<P>> {
    let mut res = vec![Modular::<P>::new(1)];
    for i in 0..n {
        res.push(res[i] * Modular::<P>::new((i + 1) as u64));
    }
    res
}

pub fn gen_inv_table<P: ModP + Copy>(n: usize) -> Vec<Modular<P>> {
    let mut res = vec![Modular::<P>::new(0)];
    for i in 1..n + 1 {
        res.push(Modular::<P>::new(1) / Modular::<P>::new(i as u64));
    }
    res
}

pub fn gen_cum<T: Add<Output = T> + Copy>(zero: T, xs: &Vec<T>) -> Vec<T> {
    let mut res = vec![zero; xs.len() + 1];
    for (i, &x) in xs.iter().enumerate() {
        res[i + 1] = res[i] + x;
    }
    res
}

fn main() {
    input! {
        new_stdin_parser = parser,
    }
    let res = solve(&mut parser);
    print!("{}", res);
}

/*------------------------------------------------------------------*/
/*-------------------------- end template --------------------------*/
/*------------------------------------------------------------------*/

use std::fmt::Write;
type Mod = Modular<Mod_1_000_000_007>;
fn solve<R: BufRead>(parser: &mut Parser<R>) -> String {
    let mut buf = String::new();
    input! {
        parser = parser,
        n: usize,
        xs: [i64; n],
    }
    let fact_table = gen_fact_table(n + 1);
    let inv_table = gen_inv_table(n + 1);
    let inv_table_cum = gen_cum(Mod::new(0), &inv_table);
    let mut res = Mod::new(0);
    for (i, &x) in xs.iter().enumerate() {
        let t = fact_table[n]
            * (inv_table_cum[i + 1 + 1] + inv_table_cum[n - i + 1] - Mod::new(1))
            * Mod::new(x as u64);
        // eprintln!("i = {}, t = {:?}", i, t);
        res += t;
    }
    writeln!(buf, "{}", res.as_u64());
    buf
}


Compiler output:
a.cc:40:10: error: too many decimal points in number
   40 |         (0..$len).map(|_| read_value!($parser, $t)).collect::<Vec<_>>()
      |          ^~~~~~~
a.cc:120:2: error: invalid preprocessing directive #[
  120 | #[allow(unused_imports)]
      |  ^
a.cc:129:2: error: invalid preprocessing directive #[
  129 | #[allow(non_camel_case_types)]
      |  ^
a.cc:130:2: error: invalid preprocessing directive #[
  130 | #[derive(Clone, Copy, Debug)]
      |  ^
a.cc:138:2: error: invalid preprocessing directive #[
  138 | #[allow(non_camel_case_types)]
      |  ^
a.cc:139:2: error: invalid preprocessing directive #[
  139 | #[derive(Clone, Copy, Debug)]
      |  ^
a.cc:147:2: error: invalid preprocessing directive #[
  147 | #[derive(Clone, Copy, PartialEq, Debug)]
      |  ^
a.cc:235:14: error: too many decimal points in number
  235 |     for i in 0..n {
      |              ^~~~
a.cc:243:14: error: too many decimal points in number
  243 |     for i in 1..n + 1 {
      |              ^~~~
a.cc:7:1: error: 'macro_rules' does not name a type
    7 | macro_rules! input {
      | ^~~~~~~~~~~
a.cc:26:1: error: 'macro_rules' does not name a type
   26 | macro_rules! input_inner {
      | ^~~~~~~~~~~
a.cc:35:1: error: 'macro_rules' does not name a type
   35 | macro_rules! read_value {
      | ^~~~~~~~~~~
a.cc:53:1: error: 'use' does not name a type
   53 | use std::io;
      | ^~~
a.cc:54:1: error: 'use' does not name a type
   54 | use std::io::BufRead;
      | ^~~
a.cc:55:1: error: 'use' does not name a type
   55 | use std::str;
      | ^~~
a.cc:60:1: error: 'pub' does not name a type
   60 | pub struct Parser<R> {
      | ^~~
a.cc:66:1: error: 'impl' does not name a type
   66 | impl Parser<io::Empty> {
      | ^~~~
a.cc:76:1: error: 'impl' does not name a type
   76 | impl<R: BufRead> Parser<R> {
      | ^~~~
a.cc:121:1: error: 'use' does not name a type
  121 | use std::cmp::*;
      | ^~~
a.cc:122:1: error: 'use' does not name a type
  122 | use std::marker::PhantomData;
      | ^~~
a.cc:123:1: error: 'use' does not name a type
  123 | use std::ops::*;
      | ^~~
a.cc:125:1: error: 'pub' does not name a type
  125 | pub trait ModP {
      | ^~~
a.cc:131:1: error: 'pub' does not name a type
  131 | pub struct Mod_1_000_000_007();
      | ^~~
a.cc:132:1: error: 'impl' does not name a type
  132 | impl ModP for Mod_1_000_000_007 {
      | ^~~~
a.cc:140:1: error: 'pub' does not name a type
  140 | pub struct Mod_998_244_353();
      | ^~~
a.cc:141:1: error: 'impl' does not name a type
  141 | impl ModP for Mod_998_244_353 {
      | ^~~~
a.cc:148:1: error: 'pub' does not name a type
  148 | pub struct Modular<P: ModP + Copy>(u64, PhantomData<P>);
      | ^~~
a.cc:150:1: error: 'impl' does not name a type
  150 | impl<P: ModP + Copy> Modular<P> {
      | ^~~~
a.cc:170:1: error: 'impl' does not name a type
  170 | impl<P: ModP + Copy> Add for Modular<P> {
      | ^~~~
a.cc:177:1: error: 'impl' does not name a type
  177 | impl<P: ModP + Copy> AddAssign for Modular<P> {
      | ^~~~
a.cc:183:1: error: 'impl' does not name a type
  183 | impl<P: ModP + Copy> Sub for Modular<P> {
      | ^~~~
a.cc:193:1: error: 'impl' does not name a type
  193 | impl<P: ModP + Copy> SubAssign for Modular<P> {
      | ^~~~
a.cc:199:1: error: 'impl' does not name a type
  199 | impl<P: ModP + Copy> Neg for Modular<P> {
      | ^~~~
a.cc:206:1: error: 'impl' does not name a type
  206 | impl<P: ModP + Copy> Mul for Modular<P> {
      | ^~~~
a.cc:216:1: error: 'impl' does not name a type
  216 | impl<P: ModP + Copy> MulAssign for Modular<P> {
      | ^~~~
a.cc:222:1: error: 'impl' does not name a type
  222 | impl<P: ModP + Copy> Div for Modular<P> {
      | ^~~~
a.cc:233:1: error: 'pub' does not name a type
  233 | pub fn gen_fact_table<P: ModP + Copy>(n: usize) -> Vec<Modular<P>> {
      | ^~~
a.cc:241:1: error: 'pub' does not name a type
  241 | pub fn gen_inv_table<P: ModP + Copy>(n: usize) -> Vec<Modular<P>> {
      | ^~~
a.cc:249:1: error: 'pub' does not name a type
  249 | pub fn gen_cum<T: Add<Output = T> + Copy>(zero: T, xs: &Vec<T>) -> Vec<T> {
      | ^~~
a.cc:257:1: error: 'fn' does not name a type
  257 | fn main() {
      | ^~
a.cc:269:1: error: 'use' does not name a type
  269 | use std::fmt::Write;
      | ^~~
a.cc:270:1: error: 'type' does not name a type; did you mean 'typeof'?
  270 | type Mod = Modular<Mod_1_000_000_007>;
      | ^~~~
      | typeof
a.cc:271:1: error: 'fn' does not name a type
  271 | fn solve<R: BufRead>(parser: &mut Parser<R>) -> String {
      | ^~