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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 1:

Input: n = 13
Output: 6

Example 2:

Input: n = 0
Output: 0

 

Constraints:

• 0 <= n <= 109

Related Topics

[Recursion] [Math] [Dynamic Programming]

Similar Questions

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

Hints

Hint 1

Beware of overflow.