Last Updated: 25 Nov, 2020

Find power of a number

Easy

Asked in companies

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Problem statement

Ninja is sitting in an examination hall. He is encountered with a problem statement, "Find ‘X’ to the power ‘N’ (i.e. ‘X’ ^ ‘N’). Where ‘X’ and ‘N’ are two integers."

Ninja was not prepared for this question at all, as this question was unexpected in the exam.

He is asking for your help to solve this problem. Help Ninja to find the answer to the problem.

Note :

For this question, you can assume that 0 raised to the power of 0 is 1.

Input format :

The first line of input contains integer ‘T’ denoting the number of test cases. Then each test case follows:

The first and only line of each test case contains two integers ‘X’ and ‘N’ (separated by space).

Output Format :

Output will contain a single integer which will be equal to X ^ N (i.e. X raise to the power N).

Output of each test cases will be printed on separate line.

Note:

You do not need to print anything, it has already been taken care of. Just implement the given function.

Constraints:

1 <= T <= 5
0 <= X <= 10
0 <= N <= 10

Time Limit: 1 sec.

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Approaches

01 Approach

The approach is to recursively call the recursive function for X and N - 1 and multiplying the value returned by the recursive function with X.

As X ^ N is same as X * (X ^ (N - 1)).

Approach :

First, let's say the recursive function is ‘POW(X, N)’ having ‘X’ and ‘N’ as arguments.
The base case for the recursive function will be for N = 0 to return the value 1. As X ^ 0 = 1 and for X = 0 to return the value 0.
Now call the function recursively with ‘X’ and ‘N - 1’ as arguments and return the value to the function by multiplying the value with ‘X’.
- return X * POW(X, N - 1).

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02 Approach

In this approach, we will call the recursive function for ‘X’ and ‘N / 2’. As X ^ N is same as

( X ^ (N / 2) ) * ( X ^ (N / 2) ) for N being an even number and X * ( X ^ (N / 2) ) * ( X ^ (N / 2) ) for N being an odd number.

Approach :

First, let's say the recursive function is ‘POW(X, N)’ having ‘X’ and ‘N’ as arguments.
The base case for the recursive function will be for N = 0 to return the value 1. As X ^ 0 = 1 and for X = 0 to return the value 0.
For N being even integer:
- return POW(X, N) * POW(X, N).
For N being odd integer:
- return X * POW(X, N) * POW(X, N).

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