pub fn quot_range_orderd(n: u32, mut f: F) where F: FnMut(u32, u32, u32), { let mut p = Vec::with_capacity((n as f64).sqrt().ceil() as usize + 1); for d in 1.. { let q = n / d; p.push((d, q)); if q < d { break; } f(d, d, q); if q == d { break; } } for p in p.windows(2).rev() { let (l, r, q) = (p[1].1 + 1, p[0].1, p[0].0); f(l, r, q); } } // ---------- begin input macro ---------- // reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 macro_rules! input { (source = $s:expr, $($r:tt)*) => { let mut iter = $s.split_whitespace(); input_inner!{iter, $($r)*} }; ($($r:tt)*) => { let s = { use std::io::Read; let mut s = String::new(); std::io::stdin().read_to_string(&mut s).unwrap(); s }; let mut iter = s.split_whitespace(); input_inner!{iter, $($r)*} }; } macro_rules! input_inner { ($iter:expr) => {}; ($iter:expr, ) => {}; ($iter:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($iter, $t); input_inner!{$iter $($r)*} }; } macro_rules! read_value { ($iter:expr, ( $($t:tt),* )) => { ( $(read_value!($iter, $t)),* ) }; ($iter:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($iter, $t)).collect::>() }; ($iter:expr, chars) => { read_value!($iter, String).chars().collect::>() }; ($iter:expr, bytes) => { read_value!($iter, String).bytes().collect::>() }; ($iter:expr, usize1) => { read_value!($iter, usize) - 1 }; ($iter:expr, $t:ty) => { $iter.next().unwrap().parse::<$t>().expect("Parse error") }; } // ---------- end input macro ---------- use std::io::Write; fn run() { input! { p: i64, q: usize, ask: [(i64, i64); q], } let mut ans = vec![0; q]; let mut e = vec![]; for (i, &(l, r)) in ask.iter().enumerate() { if l <= p { if l > 1 { e.push((l - 1, -1, i)); } e.push((r.min(p), 1, i)); } } e.sort_by_key(|e| -e.0); let f = |x: i64| x * (x + 1) / 2; let mut sum = 0; quot_range_orderd(p as u32, |l, r, q| { let l = l as i64; let r = r as i64; let q = q as i64; while e.last().map_or(false, |e| e.0 <= r) { let (x, sign, k) = e.pop().unwrap(); ans[k] += sign * (sum + q * (f(x) - f(l - 1))); } sum += q * (f(r) - f(l - 1)); }); let out = std::io::stdout(); let mut out = std::io::BufWriter::new(out.lock()); for (ans, (l, r)) in ans.into_iter().zip(ask) { let ans = (r - l + 1) * p - ans; writeln!(out, "{}", ans).ok(); } } fn main() { run(); }