Number of Digit One
Desicription
Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n.
Example:
代码语言：javascript复制Input: 13
Output: 6
Explanation: Digit 1 occurred in the following numbers: 1, 10, 11, 12, 13.Solution
代码语言：javascript复制class Solution {
public:
int countDigitOne(int n) {
int count = 0;
for(long long m = 1; m <= n; m*= 10) {
count = (n / m 8) / 10 * m (n / m % 10 == 1) * (n % m 1);
}
return count;
}
};
