Digit sums divisible by d
Count integers x with L <= x <= R whose digit sum is divisible by d. Use range counting via f(R)-f(L-1). 0 <= L <= R <= 10^12, 1 <= d <= 100. Return the count.
Implement
count_digitsum_divisible(L: int, R: int, d: int) → intExamples
in
[1,20,5]out3What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
0:00 of about 35 min
solution.py
InputExpectedGot
[1,20,5]3not run yetsample