Command R+ で elixir を学ぶ (その2）ピタゴラス数

ピタゴラス数を計算する Python のプログラムを変換してみます。

Python のプログラム

pythagoras.py

#! /usr/bin/python
#
#	pythagoras.py
#
#					Apr/11/2024
#
# ------------------------------------------------------------------
import	sys
import	math
# ------------------------------------------------------------------
def add_proc(it,jt,zz,aax,ratios):
	vv = [it,jt,zz]
	ratio = float(it) / float(jt)
	if len(aax) == 0:
		aax.append(vv)
		ratios.append(ratio)
	elif (not ratio in ratios):
		aax.append(vv)
		ratios.append(ratio)
#
# ------------------------------------------------------------------
def calc_proc(nn_max):
	aax = []
	ratios = []
	xx_min = 1
	for it in range (xx_min,nn_max):
		xx2 = it * it
		for jt in range(it+1,nn_max):
			yy2 = jt * jt
			xxyy2 = xx2 + yy2
			dz = math.sqrt(xxyy2)
			zz = int(dz)
			zz2 = zz * zz
			if (xxyy2 == zz2):
				add_proc (it,jt,zz,aax,ratios)
	return aax
# ------------------------------------------------------------------
sys.stderr.write("*** 開始 ***\n")
#
nn_max = 50
results = calc_proc (nn_max)

count = len(results)
print("count = %d" % count)

for it in range(count):
	print("%d\t%d\t%d" % (results[it][0],results[it][1],results[it][2]))

sys.stderr.write("*** 終了 ***\n")
# ------------------------------------------------------------------

実行結果

$ ./pythagoras.py 
*** 開始 ***
count = 8
3	4	5
5	12	13
7	24	25
8	15	17
9	40	41
12	35	37
20	21	29
28	45	53
*** 終了 ***

Command R+ で変換した結果

pythagoras01.exs

#! /usr/bin/elixir
#
#       pythagoras.ex
#
#                                       Apr/11/2024
#
# ------------------------------------------------------------------
IO.puts "*** 開始 ***"

defmodule Pythagoras do
  def add_proc(it, jt, zz, aax, ratios) do
    vv = [it, jt, zz]
    ratio = it / jt

    if Enum.empty?(aax) do
      aax ++ [vv]
      ratios ++ [ratio]
    else
      if not Enum.member?(ratios, ratio) do
        aax ++ [vv]
        ratios ++ [ratio]
      end
    end
  end

  def calc_proc(nn_max) do
    aax = []
    ratios = []
    xx_min = 1

    for it <- xx_min..nn_max do
      xx2 = it * it

      for jt <- it + 1..nn_max do
        yy2 = jt * jt
        xxyy2 = xx2 + yy2
        dz = :math.sqrt(xxyy2)
        zz = round(dz)
        zz2 = zz * zz

        if xxyy2 == zz2 do
          add_proc(it, jt, zz, aax, ratios)
        end
      end
    end

    aax
  end
end

# ------------------------------------------------------------------
nn_max = 50
results = Pythagoras.calc_proc(nn_max)

count = Enum.count(results)
IO.puts("count = #{count}")

for i <- 0..count-1 do
  IO.inspect(Enum.at(results, i))
end

IO.puts "*** 終了 ***"

実行結果

$ ./pythagoras01.exs 
*** 開始 ***
warning: the result of evaluating operator '++'/2 is ignored (suppress the warning by assigning the expression to the _ variable)
  pythagoras01.exs:16

warning: the result of evaluating operator '++'/2 is ignored (suppress the warning by assigning the expression to the _ variable)
  pythagoras01.exs:20

count = 0
nil
nil
*** 終了 ***