SquareRootLogarithmic.js

/**
 * @function squareRootLogarithmic
 * @description
 * Return the square root of 'num' rounded down
 * to the nearest integer.
 * More info: https://leetcode.com/problems/sqrtx/
 * @param {Number} num Number whose square of root is to be found
 * @returns {Number} Square root
 * @see [BinarySearch](https://en.wikipedia.org/wiki/Binary_search_algorithm)
 * @example
 * const num1 = 4
 * logarithmicSquareRoot(num1) // ====> 2
 * @example
 * const num2 = 8
 * logarithmicSquareRoot(num1) // ====> 2
 *
 */
const squareRootLogarithmic = (num) => {
 if (typeof num !== 'number') {
 throw new Error('Input data must be numbers')
 }
 let answer = 0
 let sqrt = 0
 let edge = num

 while (sqrt <= edge) {
 const mid = Math.trunc((sqrt + edge) / 2)
 if (mid * mid === num) {
 return mid
 } else if (mid * mid < num) {
 sqrt = mid + 1
 answer = mid
 } else {
 edge = mid - 1
 }
 }

 return answer
}

export { squareRootLogarithmic }