1067. Digit Count in Range
Given an integer d between 0 and 9, and two positive integers low and high as lower and upper bounds, respectively. Return the number of times that d occurs as a digit in all integers between low and high, including the bounds low and high.
Input: d = 1, low = 1, high = 13
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.
Input: d = 3, low = 100, high = 250
The digit d=3 occurs 35 times in 103,113,123,130,131,...,238,239,243.