| Author: | andy |
|---|---|
| Mode: | factor |
| Date: | Wed, 20 Jan 2010 11:22:33 |
: fib-iter ( x y -- x y ) [ + ] keep swap ; : fib-sum-iter ( x y z -- x y z ) swap [ drop [ + ] keep ] keep swap ; : fib-even-sum ( -- x ) 0 0 1 [ dup 1000000 < ] [ dup even? [ fib-sum-iter ] when fib-iter ] while 2drop ;