8 lines
283 B
Ruby
8 lines
283 B
Ruby
|
#Given a binary number unset the rightmost set bit.
|
||
|
|
#Algorithm: The biwise "&" of any number n with n-1 unsets the rightmost set bit
|
||
|
|
#e.g. 5=101 ,5-1=4=100 ,5&4=(101)&(100)=100(result with rightmost bit unset)
|
||
|
|
|
||
|
|
def unset_rightmost(n)
|
||
|
|
return n&(n-1)
|
||
|
|
end
|
||
|
|
unset_rightmost(3) # => 2
|