I am simulating the shuffling of a card deck. So for now lets say i want the 52 cards in random order. Once a card is dealt it can no longer be dealt again.
This will give me 52 random numbers from 1-52. How canI implement it so all 52 numbers will be called and none will be repeated?
for i = 1,52 do
j=math.random(1, 52)
print (j)
end
A different strategy would seem to make sense. Populate an array with the numbers 1-52, then randomly swap positions… (which guarantees no repeats of course).
Good stuff thank you! I got the first part down, populating the array with numbers 1-52:
local cards={}
for i = 1,52 do
cards[i]=i
print (cards[i])
end
How do I go about randomly swapping positions?
You want to shuffle the table. There are numerous posts in the forums about shuffling a table. Here is the one I use:
local function shuffleTable(t) local rand = math.random assert(t, "table.shuffle() expected a table, got nil") local iterations = #t local j for i = iterations, 2, -1 do j = rand(i) t[i], t[j] = t[j], t[i] end end
Rob
http://snippets.luacode.org/snippets/Shuffle_array_145
And if you don’t like that solution there are many more:
Seems the link at the top is dead. Here is a variation on that code:
-- Shuffles the contents of a table. -- -- Returns nil. -- function table.shuffle(t) -- Algorithm altered and borrowed from http://snippets.luacode.org/snippets/Shuffle\_array\_145 local n, order = #t, {}; for i=1,n do order[i] = { rnd = math.random(), val = t[i] }; end table.sort(order, function(a,b) return a.rnd \< b.rnd; end); for i=1,n do t[i] = order[i].val; end endI am experimenting making a blackjack game and i saw a video that you have already done one. Do you still have the source code for sale? I don’t care if it’s pre-grapghics 2.0. I just want to read/rewrite the code and learn whatever I can. Thanks.
Sorry. I’m afraid that code is no longer for sale.
A different strategy would seem to make sense. Populate an array with the numbers 1-52, then randomly swap positions… (which guarantees no repeats of course).
Good stuff thank you! I got the first part down, populating the array with numbers 1-52:
local cards={}
for i = 1,52 do
cards[i]=i
print (cards[i])
end
How do I go about randomly swapping positions?
You want to shuffle the table. There are numerous posts in the forums about shuffling a table. Here is the one I use:
local function shuffleTable(t) local rand = math.random assert(t, "table.shuffle() expected a table, got nil") local iterations = #t local j for i = iterations, 2, -1 do j = rand(i) t[i], t[j] = t[j], t[i] end end
Rob
http://snippets.luacode.org/snippets/Shuffle_array_145
And if you don’t like that solution there are many more:
Seems the link at the top is dead. Here is a variation on that code:
-- Shuffles the contents of a table. -- -- Returns nil. -- function table.shuffle(t) -- Algorithm altered and borrowed from http://snippets.luacode.org/snippets/Shuffle\_array\_145 local n, order = #t, {}; for i=1,n do order[i] = { rnd = math.random(), val = t[i] }; end table.sort(order, function(a,b) return a.rnd \< b.rnd; end); for i=1,n do t[i] = order[i].val; end endI am experimenting making a blackjack game and i saw a video that you have already done one. Do you still have the source code for sale? I don’t care if it’s pre-grapghics 2.0. I just want to read/rewrite the code and learn whatever I can. Thanks.
Sorry. I’m afraid that code is no longer for sale.