Repdigits in Range

Difficulty: 1200 4000 ms 128 MB

math digit-dp

Count integers in [L, R] all of whose digits are identical (like 777).

Input: one line with two integers L and R.

Output: the count of repdigits in [L, R].

Constraints:

• 1 ≤ L ≤ R ≤ 10¹⁸

Sample Tests

1 30

11

100 800

7

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