{leetcode}/problems/number-of-digit-one/[LeetCode - Number of Digit One^]
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.
link:{sourcedir}/_0233_NumberOfDigitOne.java[role=include]