authorgravatar for 8972248+oittaa@users.noreply.github.comoittaa <8972248+oittaa@users.noreply.github.com> 2025-03-24 16:07:40+01:00
committergravatar for noreply@github.comGitHub <noreply@github.com> 2025-03-24 16:07:40+01:00
logc1db72cdbcddb59aa4e9960f4c07de9781b296f6
tree390e143369e9193dfe9cfbf1399623ee8f1700f1
parent9f8d938d3825bd5d4d2d7f76907075d13b04d8e1
signaturebadge-check Signed by PGP key B5690EEEBB952194

std.math: Add least common multiple (lcm)

2 files changed, 31 insertions(+), 0 deletions(-)

lib/std/math.zig+2
...@@ -235,6 +235,7 @@ pub const sinh = @import("math/sinh.zig").sinh;...@@ -235,6 +235,7 @@ pub const sinh = @import("math/sinh.zig").sinh;
235pub const cosh = @import("math/cosh.zig").cosh;235pub const cosh = @import("math/cosh.zig").cosh;
236pub const tanh = @import("math/tanh.zig").tanh;236pub const tanh = @import("math/tanh.zig").tanh;
237pub const gcd = @import("math/gcd.zig").gcd;237pub const gcd = @import("math/gcd.zig").gcd;
238pub const lcm = @import("math/lcm.zig").lcm;
238pub const gamma = @import("math/gamma.zig").gamma;239pub const gamma = @import("math/gamma.zig").gamma;
239pub const lgamma = @import("math/gamma.zig").lgamma;240pub const lgamma = @import("math/gamma.zig").lgamma;
240241
...@@ -395,6 +396,7 @@ test {...@@ -395,6 +396,7 @@ test {
395 _ = cosh;396 _ = cosh;
396 _ = tanh;397 _ = tanh;
397 _ = gcd;398 _ = gcd;
399 _ = lcm;
398 _ = gamma;400 _ = gamma;
399 _ = lgamma;401 _ = lgamma;
400402
lib/std/math/lcm.zig created+29
...@@ -0,0 +1,29 @@
1//! Least common multiple (https://mathworld.wolfram.com/LeastCommonMultiple.html)
2const std = @import("std");
3
4/// Returns the least common multiple (LCM) of two integers (`a` and `b`).
5/// For example, the LCM of `8` and `12` is `24`, that is, `lcm(8, 12) == 24`.
6/// If any of the arguments is zero, then the returned value is 0.
7pub fn lcm(a: anytype, b: anytype) @TypeOf(a, b) {
8 // Behavior from C++ and Python
9 // If an argument is zero, then the returned value is 0.
10 if (a == 0 or b == 0) return 0;
11 return @abs(b) * (@abs(a) / std.math.gcd(@abs(a), @abs(b)));
12}
13
14test lcm {
15 const expectEqual = std.testing.expectEqual;
16
17 try expectEqual(lcm(0, 0), 0);
18 try expectEqual(lcm(1, 0), 0);
19 try expectEqual(lcm(-1, 0), 0);
20 try expectEqual(lcm(0, 1), 0);
21 try expectEqual(lcm(0, -1), 0);
22 try expectEqual(lcm(7, 1), 7);
23 try expectEqual(lcm(7, -1), 7);
24 try expectEqual(lcm(8, 12), 24);
25 try expectEqual(lcm(-23, 15), 345);
26 try expectEqual(lcm(120, 84), 840);
27 try expectEqual(lcm(84, -120), 840);
28 try expectEqual(lcm(1216342683557601535506311712, 436522681849110124616458784), 16592536571065866494401400422922201534178938447014944);
29}