giles
07de86365e
Some checks failed
Test, Build, and Deploy / test-build-deploy (push) Failing after 27s
Walks digits right-to-left, doubles every other starting from the
second-from-right; if a doubled value > 9, subtract 9. Sum must be
divisible by 10:
let luhn s =
let n = String.length s in
let total = ref 0 in
for i = 0 to n - 1 do
let d = Char.code s.[n - 1 - i] - Char.code '0' in
let v = if i mod 2 = 1 then
let dd = d * 2 in
if dd > 9 then dd - 9 else dd
else d
in
total := !total + v
done;
!total mod 10 = 0
Test cases:
'79927398713' valid
'79927398710' invalid
'4532015112830366' valid (real Visa test)
'1234567890123456' invalid
sum = 2
Tests right-to-left index walk via 'n - 1 - i', Char.code '0'
arithmetic for digit conversion, and nested if-then-else.
75 baseline programs total.
80 lines
1.6 KiB
JSON
80 lines
1.6 KiB
JSON
{
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"ackermann.ml": 125,
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"anagram_check.ml": 2,
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"anagrams.ml": 3,
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"atm.ml": 120,
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"bag.ml": 3,
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"bf_full.ml": 6,
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"bisect.ml": 141,
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"bigint_add.ml": 28,
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"bits.ml": 21,
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"balance.ml": 3,
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"base_n.ml": 17,
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"bfs.ml": 6,
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"btree.ml": 39,
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"brainfuck.ml": 75,
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"bsearch.ml": 7,
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"caesar.ml": 215,
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"calc.ml": 13,
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"closures.ml": 315,
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"coin_change.ml": 6,
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"csv.ml": 10,
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"exception_handle.ml": 4,
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"exception_user.ml": 26,
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"expr_eval.ml": 16,
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"expr_simp.ml": 22,
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"factorial.ml": 3628800,
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"fraction.ml": 7,
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"frequency.ml": 5,
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"gcd_lcm.ml": 60,
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"grep_count.ml": 3,
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"group_consec.ml": 53,
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"hailstone.ml": 111,
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"hanoi.ml": 1023,
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"hist.ml": 75,
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"fizzbuzz.ml": 57,
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"flatten_tree.ml": 28,
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"list_ops.ml": 30,
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"luhn.ml": 2,
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"mat_mul.ml": 621,
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"max_path_tree.ml": 11,
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"mod_inverse.ml": 27,
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"json_pretty.ml": 24,
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"kadane.ml": 6,
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"lambda_calc.ml": 7,
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"levenshtein.ml": 11,
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"memo_fib.ml": 75025,
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"mortgage.ml": 1073,
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"merge_sort.ml": 44,
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"module_use.ml": 3,
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"newton_sqrt.ml": 1414,
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"mutable_record.ml": 10,
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"option_match.ml": 5,
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"palindrome.ml": 4,
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"pascal.ml": 252,
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"pi_leibniz.ml": 314,
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"prefix_sum.ml": 66,
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"pretty_table.ml": 64,
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"poly_stack.ml": 5,
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"prime_factors.ml": 17,
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"queens.ml": 2,
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"quicksort.ml": 44,
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"roman.ml": 44,
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"rpn.ml": 9,
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"run_length.ml": 11,
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"safe_div.ml": 20,
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"shuffle.ml": 55,
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"subset_sum.ml": 8,
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"tic_tac_toe.ml": 1,
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"word_freq.ml": 8,
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"zigzag.ml": 55,
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"zip_unzip.ml": 1000,
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"sieve.ml": 15,
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"sum_squares.ml": 385,
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"triangle.ml": 11,
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"twosum.ml": 5,
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"unique_set.ml": 9,
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"validate.ml": 417,
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"word_count.ml": 3
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}
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