Time Complexity(TC)

TC while counting digits of a number

O(log10(N)) ➔ In every iteration we are dividing N by 10 (equivalent to the number of digits in N).

$log_{10} n$ is the standard mathematical notation for the number of digits/iterations, where $n$ is the value of the input number.

But in interview, be careful, tell both ways

1. When $n$ is the number , since we are dividing the number by 10 at every step the time complexity follows a logarithmic scale, then the TC is $log_{10}n$

2. When $D$ is considered as number of digits, then the time complexity can be represented as $O(D)$