diff options
Diffstat (limited to 'challenge-113/abigail/lua')
| -rw-r--r-- | challenge-113/abigail/lua/ch-1.lua | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/challenge-113/abigail/lua/ch-1.lua b/challenge-113/abigail/lua/ch-1.lua index 36bd8e8afd..4de70d106c 100644 --- a/challenge-113/abigail/lua/ch-1.lua +++ b/challenge-113/abigail/lua/ch-1.lua @@ -8,29 +8,35 @@ -- Run as: lua ch-1.lua < input-file -- -local tens = {0, 1, 2, 1, 0, 2, 6, 3, 8} +-- +-- For a description of the algorithm, and the proof why this is correct: +-- https://abigail.github.io/HTML/Perl-Weekly-Challenge/week-113-1.html +-- + +local gcds = {1, 2, 1, 2, 5, 2, 1, 2, 1} for line in io . lines () do local _, _, N, D = line : find ("([0-9]+)%s+([0-9])") N = tonumber (N) D = tonumber (D) - local D10 = 10 * D if D == 0 - then D10 = 100 + then if N >= 100 or N % 10 == 0 + then print (1) + else print (0) + end + goto end_loop end - if (N >= D10) or (D == 0 and N % 10 == 0) - or (D > 0 and N % D == 0) + + if N >= D * 10 then print (1) goto end_loop end - if D > 0 - then for i = 1, tens [D] - do local T = N - 10 * i - D - if T >= 0 and T % D == 0 - then print (1) - goto end_loop - end + for i = 0, D / gcds [D] - 1 + do local T = N - 10 * i - D + if T >= 0 and T % D == 0 + then print (1) + goto end_loop end end |