diff options
Diffstat (limited to 'challenge-136/abigail/lua/ch-2.lua')
| -rw-r--r-- | challenge-136/abigail/lua/ch-2.lua | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/challenge-136/abigail/lua/ch-2.lua b/challenge-136/abigail/lua/ch-2.lua index 06d92984f4..e955e8cc81 100644 --- a/challenge-136/abigail/lua/ch-2.lua +++ b/challenge-136/abigail/lua/ch-2.lua @@ -8,11 +8,19 @@ -- Run as: lua ch-2.lua < input-file -- +local cache = {} + function _count (target, this_fib, prev_fib) - if target < this_fib then return 0 end - if target == this_fib then return 1 end - return (_count (target - this_fib, this_fib + prev_fib, this_fib) + - _count (target, this_fib + prev_fib, this_fib)) + local key = target .. ";" .. this_fib + if cache [key] == nil then + if target < this_fib then cache [key] = 0 + elseif target == this_fib then cache [key] = 1 + else cache [key] = + _count (target - this_fib, this_fib + prev_fib, this_fib) + + _count (target, this_fib + prev_fib, this_fib) + end + end + return cache [key] end function count (target) |