Anonymous user
Permutations: Difference between revisions
→{{header|Lua}}
(Updated third D entry) |
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Line 2,026:
{2, 1, 3}
{1, 2, 3}
</pre>
<lang lua>
-- Iterative version
function ipermutations(a,b)
if a==0 then return end
local taken = {} local slots = {}
for i=1,a do slots[i]=0 end
for i=1,b do taken[i]=false end
local index = 1
while index > 0 do repeat
repeat slots[index] = slots[index] + 1
until slots[index] > b or not taken[slots[index]]
if slots[index] > b then
slots[index] = 0
index = index - 1
if index > 0 then
taken[slots[index]] = false
end
break
else
taken[slots[index]] = true
end
if index == a then
for i=1,a do io.write(slots[i]) io.write(" ") end
io.write("\n")
taken[slots[index]] = false
break
end
index = index + 1
until true end
end
ipermutations(3, 3)
</lang>
<pre>
1 2 3
1 3 2
2 1 3
2 3 1
3 1 2
3 2 1
</pre>
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