RosettaCodeData/Task/Ethiopian-multiplication/Java/ethiopian-multiplication-7....

16 lines
368 B
Java

def halve: (./2) | floor;
def double: 2 * .;
def isEven: . % 2 == 0;
def ethiopian_multiply(a;b):
def pairs: recurse( if .[0] > 0
then [ (.[0] | halve), (.[1] | double) ]
else empty
end );
reduce ([a,b] | pairs
| select( .[0] | isEven | not)
| .[1] ) as $i
(0; . + $i) ;