number_of_digit_one

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233. Number of Digit One (Hard)

Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n.

Example:

Input: 13
Output: 6 
Explanation: Digit 1 occurred in the following numbers: 1, 10, 11, 12, 13.

Related Topics

[Math]

Similar Questions

1. Factorial Trailing Zeroes (Easy)
2. Digit Count in Range (Hard)

Hints

Hint 1

Beware of overflow.