RosettaCodeData/Task/Hofstadter-Q-sequence/Forth/hofstadter-q-sequence.fth
2023-07-01 13:44:08 -04:00

27 lines
318 B
Forth

100000 constant N
: q ( n -- addr ) cells here + ;
: qinit
1 0 q !
1 1 q !
N 2 do
i i 1- q @ - q @
i i 2 - q @ - q @
+ i q !
loop ;
: flips
." flips: "
0 N 1 do
i q @ i 1- q @ < if 1+ then
loop . cr ;
: qprint ( n -- )
0 do i q @ . loop cr ;
qinit
10 qprint
999 q @ . cr
flips
bye