gcd

function gcd( x [, ...] ) --> res

Description

Returns the greatest common divisor of one or more integers. The greatest common divisor is the largest integer that divides all numbers without a remainder.

Parameters

x

Required number. If the number value is not an integer, it is truncated.

…

Optional numbers. If any number value is not an integer, it is truncated.

Return Values

res

The greatest common divisor.

Code

--ZFUNC-gcd-v1
local function gcd( x, ... ) --> res
   local function pgcd( m, n )
      while m ~= 0 do
         m, n = n % m, m
      end
      return n
   end

   local res = math.floor( x )
   for _, n in ipairs{ ... } do
      if n < 0 then return math.sqrt( -1 ) end
      res = pgcd( res, math.floor( n ) )
   end

   return res
end

return gcd

Examples

local t = require( "taptest" )
local gcd = require( "gcd" )

t( gcd( 5, 2 ), 1 )
t( gcd( 24, 36 ), 12 )
t( gcd( 7, 1 ), 1 )
t( gcd( 5, 0 ), 5 )
t( gcd( 2, 3, 5 ), 1 )

t()

Inspired by

See also