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27 lines
966 B
JavaScript
27 lines
966 B
JavaScript
import { isEven } from './IsEven'
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/**
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* This algorithm is divide the n by 2 every time and pass this to recursive call to find the result of smaller result.
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* why? Because
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* x^n => [if n is even] x^(n / 2) * x^(n / 2) (example : 7^4 => 7^2 * 7^2)
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* [if n is odd] x^(n / 2) * x^(n / 2) * x (example : 7^5 => 7^2 * 7^2 * 7)
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* and repeat the above step until we reach to the base case.
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*
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* @function PowLogarithmic
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* @description Given two integers x and n, return x^n in logarithmic complexity.
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* @param {Integer} x - The input integer
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* @param {Integer} n - The input integer
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* @return {Integer} - Returns x^n.
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* @see [Pow-Logarithmic](https://www.geeksforgeeks.org/write-a-c-program-to-calculate-powxn/)
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*/
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const powLogarithmic = (x, n) => {
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if (n === 0) return 1
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const result = powLogarithmic(x, Math.floor(n / 2))
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if (isEven(n)) {
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return result * result
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}
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return result * result * x
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}
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export { powLogarithmic }
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