use std::io::stdin; #[derive(Clone, Copy, Debug, PartialEq, Eq)] struct TestCase{ n: usize, x: i64, } impl TestCase{ fn solve(&self) -> Option> { let n = self.n as i64; let x = self.x; let min_sum = n * ( n +1 )/2; if x < min_sum{ None }else{ let ret = (1..n).chain(std::iter::once(x - n * (n-1)/2)).collect(); Some(ret) } } } struct Problem { n_case: usize, test_cases: Vec, } impl Problem { fn read(mut r: R) -> Problem { let n_case = r.read_usize_1(); let test_cases = (0..n_case).map(|_| { let (n, x) = r.read_i64_2(); let n = n as usize; TestCase { n, x } }).collect(); Problem { n_case, test_cases } } fn solve(&self) -> Answer { let ans = self.test_cases.iter().copied().map(|test_case| { test_case.solve() }).collect(); Answer { ans } } } #[derive(Clone, Debug, PartialEq, Eq)] struct Answer { ans: Vec>>, } impl Answer { fn print(&self) { for row in &self.ans{ if let Some(row) = row{ print_vec_1line(row); }else{ println!("-1"); } } } } pub fn print_vec_1line(arr: &[T]) { let msg = arr.iter().map(|x| format!("{:?}", x)).collect::>().join(" "); println!("{}", msg); } fn main() { Problem::read(ProconReader::new(stdin().lock())).solve().print(); } #[cfg(test)] mod tests { use super::*; #[allow(dead_code)] fn check(input: &str, expected: Answer) { let actual = Problem::read(ProconReader::new(input.as_bytes())).solve(); assert_eq!(expected, actual); } #[test] fn test_problem() { let _input = " 3 4 " .trim(); // check(_input, Answer { ans: 7 }); } } // ====== snippet ====== #[allow(unused_imports)] use myio::*; pub mod myio { use std::io::BufRead; pub trait IProconReader { fn read_line(&mut self) -> String; fn read_bytes(&mut self) -> Vec { self.read_line().as_bytes().to_vec() } fn read_any_1(&mut self) -> T where T: std::str::FromStr, T::Err: std::fmt::Debug, { let buf = self.read_line(); buf.parse::().unwrap() } fn read_any_2(&mut self) -> (T0, T1) where T0: std::str::FromStr, T0::Err: std::fmt::Debug, T1: std::str::FromStr, T1::Err: std::fmt::Debug, { let buf = self.read_line(); let splitted = buf.trim().split(' ').collect::>(); let a0 = splitted[0].parse::().unwrap(); let a1 = splitted[1].parse::().unwrap(); (a0, a1) } fn read_any_3(&mut self) -> (T0, T1, T2) where T0: std::str::FromStr, T0::Err: std::fmt::Debug, T1: std::str::FromStr, T1::Err: std::fmt::Debug, T2: std::str::FromStr, T2::Err: std::fmt::Debug, { let buf = self.read_line(); let splitted = buf.trim().split(' ').collect::>(); let a0 = splitted[0].parse::().unwrap(); let a1 = splitted[1].parse::().unwrap(); let a2 = splitted[2].parse::().unwrap(); (a0, a1, a2) } fn read_any_4(&mut self) -> (T0, T1, T2, T3) where T0: std::str::FromStr, T0::Err: std::fmt::Debug, T1: std::str::FromStr, T1::Err: std::fmt::Debug, T2: std::str::FromStr, T2::Err: std::fmt::Debug, T3: std::str::FromStr, T3::Err: std::fmt::Debug, { let buf = self.read_line(); let splitted = buf.trim().split(' ').collect::>(); let a0 = splitted[0].parse::().unwrap(); let a1 = splitted[1].parse::().unwrap(); let a2 = splitted[2].parse::().unwrap(); let a3 = splitted[3].parse::().unwrap(); (a0, a1, a2, a3) } fn read_vec_any(&mut self) -> Vec where T: std::str::FromStr, T::Err: std::fmt::Debug, { let buf = self.read_line(); buf.trim().split(' ').map(|s| s.parse::().unwrap()).collect::>() } fn read_vec_i64(&mut self) -> Vec { self.read_vec_any::() } fn read_vec_usize(&mut self) -> Vec { self.read_vec_any::() } fn read_vec_str(&mut self) -> Vec { self.read_vec_any::() } fn read_i64_1(&mut self) -> i64 { self.read_any_1::() } fn read_i64_2(&mut self) -> (i64, i64) { self.read_any_2::() } fn read_i64_3(&mut self) -> (i64, i64, i64) { self.read_any_3::() } fn read_i64_4(&mut self) -> (i64, i64, i64, i64) { self.read_any_4::() } fn read_usize_1(&mut self) -> usize { self.read_any_1::() } fn read_usize_2(&mut self) -> (usize, usize) { self.read_any_2::() } fn read_usize_3(&mut self) -> (usize, usize, usize) { self.read_any_3::() } fn read_usize_4(&mut self) -> (usize, usize, usize, usize) { self.read_any_4::() } } pub struct ProconReader { buf_read: R, } impl ProconReader { pub fn new(buf_read: R) -> ProconReader { ProconReader { buf_read } } } impl IProconReader for ProconReader { fn read_line(&mut self) -> String { let mut buffer = String::new(); self.buf_read.read_line(&mut buffer).unwrap(); buffer.trim().to_string() } } }