All possible numbers of N digits and base B without leading zeros

Given a number of digits 'N' and base 'B', the task is to count all the 'N' digit numbers without leading zeros that are in base 'B'

Examples:  

Input: N = 2, B = 2
Output: 2
All possible numbers without 
leading zeros are 10 and 11.

Input: N = 5, B = 8
Output: 28672

Approach:  

• If the base is 'B' then every digit of the number can take any value within the range [0, B-1].
• So, B'N' digit numbers are possible with base 'B' (including the numbers with leading zeros).
• And, if we fix the first digit as '0' then the rest of the 'N-1' digits can form a total of Bnumbers.
• So, the total number of 'N' digit numbers with base 'B' possible without leading zeros are B- B.

Below is the implementation of the above approach: 

3072

Time Complexity: O(logn), since pow function takes logn time to find the power of a number to base n.

Auxiliary Space: O(1), since no extra space has been taken.