RosettaCodeData/Task/Partition-function-P/Lingo/partition-function-p.lingo

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-- returns number of partitions of n
on partitions(n, res_table)
if n < 2 then return 1
if voidP(res_table) then
res_table = []
res_table[n] = 0
else if res_table[n] then
return res_table[n]
end if
res = 0
i = 0
param = 1
repeat while param <= n
if i mod 4 < 2 then
res = res + partitions(n - param, res_table)
else
res = res - partitions(n - param, res_table)
end if
if i mod 2 then
param = param + i + 2
else
param = param + i / 2 + 1
end if
i = i + 1
end repeat
res_table[n] = res
return res
end