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Calculate Power of a Number

Calculate Power of a Number

Given a double number, x, and an integer, n, write a function to calculate x raised to the power n.

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Statement

Given a double number, xx, and an integer, nn, implement a function to calculate xx raised to the power nn.

Example:

Given input

Power

power(0, 0)

1.000

power(2, 5)

32.000

power(3, 4)

81.000

power(1.5, 3)

3.375

power(2, -2)

0.250

Sample input

pow(2,5)

Expected output

32

Try it yourself

#include <iostream>
#include <cmath>
#include <vector>
using namespace std;
double Power(double x, int n) {
	//TODO: Write - Your - Code
	return x;
}

Solution

A simple algorithm for this problem is to multiply x with itself by n times:

We can reduce the number of multiplications, in a classic divide and conquer approach, exploiting this property of exponents:

  • xn=xn2×xn2x^n=x^{\frac{n}{2}} \times x^{\frac{n}{2}}
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