Nth root of a number

#1

I am not able to derive the logic behind the problem .Please help

#2

Hey @anishmittal
According to the question,
You are given two integers n and k. Find the greatest integer x, such that, x^k <= n.

For the test cases given:
2
10000 1
1000000000000000 10

In the first case, n = 10000 and k = 1, so the maximum integer x such that x^1 <= 10000 is 10000, coz if we take integers greater than 10000, then x^k will become > n, hence the greatest integer required is 10000.
In the second case, the greatest integer x such that x^10 is less than or equal to 1000000000000000 is 31 coz 32^10 is greater than 1000000000000000.

To solve this question, you can simply use linear search from 1 till n, coz the largest answer can be n itself, but the range of n is given as 10^15, so the linear search approach is going to give a TLE. Hence we use binary search,
Try writing the code and do ask if you face any problems.

#3

i am facing a dilema of how to replace pow function because if i make my own power function using loop then complexity will shoot o(n3) ,if not power function won’t handle such big values

#4

@anishmittal you can use the normal inbuilt pow function in C++ to solve this problem. the arguments going inside pow will be x and k, which will be in integer range, so it’s cool to use inbuilt pow function.

#5

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