malachite_nz/gaussian_integer/comparison/eq_abs.rs
1// Copyright © 2026 Mikhail Hogrefe
2//
3// This file is part of Malachite.
4//
5// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
6// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
7// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.
8
9use crate::gaussian_integer::GaussianInteger;
10use core::cmp::Ordering::Equal;
11use malachite_base::num::comparison::traits::{EqAbs, OrdAbs};
12
13impl EqAbs for GaussianInteger {
14 /// Determines whether the absolute values of two [`GaussianInteger`]s are equal.
15 ///
16 /// The absolute value of a complex number is its distance from the origin, so this is
17 /// equivalent to comparing squared absolute values. The comparison delegates to [`OrdAbs`],
18 /// whose componentwise and crosswise screens usually decide the answer without computing the
19 /// squared absolute values.
20 ///
21 /// # Worst-case complexity
22 /// $T(n) = O(n \log n \log\log n)$
23 ///
24 /// $M(n) = O(n \log n)$
25 ///
26 /// where $T$ is time, $M$ is additional memory, and $n$ is the maximum number of significant
27 /// bits of the real and imaginary parts of `self` and `other`.
28 ///
29 /// # Examples
30 /// ```
31 /// use malachite_base::num::comparison::traits::EqAbs;
32 /// use malachite_nz::gaussian_integer::GaussianInteger;
33 /// use std::str::FromStr;
34 ///
35 /// let x = GaussianInteger::from_str("1+2i").unwrap();
36 /// let y = GaussianInteger::from_str("-2+i").unwrap();
37 /// assert!(x.eq_abs(&y));
38 ///
39 /// let x = GaussianInteger::from_str("2+2i").unwrap();
40 /// let y = GaussianInteger::from_str("3i").unwrap();
41 /// // |2+2i|^2 = 8 and |3i|^2 = 9
42 /// assert_eq!(x.eq_abs(&y), false);
43 /// ```
44 #[inline]
45 fn eq_abs(&self, other: &Self) -> bool {
46 self.cmp_abs(other) == Equal
47 }
48}