Nth root of a number using log

Given two integers N and K, the task is to find the N^th root of the K. 

Examples: 

Input: N = 3, K = 8 
Output: 2.00 
Explanation: 
Cube root of 8 is 2. i.e. 2³ = 8

Input: N = 2, K = 16 
Output: 4.00 
Explanation: 
Square root of 16 is 4, i.e. 4² = 16 
 

Approach: The idea is to use logarithmic function to find the N^th root of K.

Let D be our N^th root of the K, 
Then, 
Apply log_K on both the sides - 
=> 
=> 
=> 
 

Below is the implementation of the above approach:  

3.000000

Time Complexity: O(1)

Auxiliary Space: O(1)