So i'm learning Lua. I find it great so far.
I'm trying to write code "thinking in Lua" not just "thinking
in C, then translating to Lua".
So i'm going through Project Euler' problems. I recently
solved this one :
http://projecteuler.net/index.php?section=problems&id=14
Using this code :
function
mesure(n)
local i = 0
while n ~= 1 do
if n % 2 == 0 then n = n / 2
else n = 3*n + 1 end
i = i + 1
end
return i
end
local begin = os.time()
local max = 0
local maxi = 0
for i = 1, arg[1] or 10 do
local new = mesure(i)
if new > max then
max = new
maxi = i
end
end
io.write("Done. ", os.difftime(os.time(), begin), "s.\n")
io.write("i = ", maxi)
When running it until 1,000,000 it finishes in about 15
seconds. (I have a 1.83Ghz processor).
I'm not really concerned about performance, and i'm
sure there's a better algorithm for solving this problem.
But an
equivalent algorithm
in C finishes about 6 times faster.
Is this what one should expect from Lua ?
I'm also concerned about the style of my code. Is this
making a good use of Lua ?
I don't get the reflex of using the beautiful things it
provides yet, like the generic for, multiple assignments,
function as prime values, etc.
How do you do that ? :D
