1067. Digit Count in Range

https://leetcode.com/problems/digit-count-in-range

Description

Given a single-digit integer d and two integers low and high, return the number of times that d occurs as a digit in all integers in the inclusive range [low, right].

Example 1:

**Input:** d = 1, low = 1, high = 13
**Output:** 6
**Explanation:** The digit d = 1 occurs 6 times in 1, 10, 11, 12, 13.
Note that the digit d = 1 occurs twice in the number 11.

Example 2:

**Input:** d = 3, low = 100, high = 250
**Output:** 35
**Explanation:** The digit d = 3 occurs 35 times in 103,113,123,130,131,...,238,239,243.

Constraints:

• 0 <= d <= 9

• 1 <= low <= high <= 2 * 108

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