RosettaCodeData/Task/Perfect-numbers/Lambdatalk/perfect-numbers-2.lambdatalk

27 lines
806 B
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{def lt_perfect
{def lt_perfect.sum
{lambda {:n :sum :i}
{if {> :i 1}
then {lt_perfect.sum :n
{if {= {% :n :i} 0}
then {+ :sum :i {floor {/ :n :i}}}
else :sum}
{- :i 1}}
else :sum }}}
{lambda {:n}
{let { {:n :n}
{:sqrt {floor {sqrt :n}}}
{:sum {lt_perfect.sum :n 1 {- {floor {sqrt :n}} 0} }}
{:foo {if {= {* :sqrt :sqrt} :n}
then 0
else {floor {/ :n :sqrt}}}}
} {= :n {if {= {% :n :sqrt} 0}
then {+ :sum :sqrt :foo}
else :sum}} }}}
-> lt_perfect
-> {S.replace \s by space in
{S.map {lambda {:i} {if {lt_perfect :i} then :i else}}
{S.serie 6 10000 2}}}
-> 28 496 8128 // 7500ms