algorithm: logarithmic square root (TheAlgorithms#1259)

* algorithm: add SquareRootLogarithmic algo and a test for it * fix: fix spelling errors * refactor: rename a variable "e" --> "edge"

Author: Saimon398

Maths/SquareRootLogarithmic.js

@@ -0,0 +1,41 @@
+/**
+ * @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 }

Maths/test/SquareRootLogarithmic.test.js

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+import { squareRootLogarithmic } from '../SquareRootLogarithmic'
+
+describe('SquareRootLogarithmic', () => {
+ test('Finding the square root of a positive integer', () => {
+ expect(squareRootLogarithmic(4)).toEqual(2)
+ expect(squareRootLogarithmic(16)).toEqual(4)
+ expect(squareRootLogarithmic(8)).toEqual(2)
+ })
+ test('Throwing an exception', () => {
+ expect(() => squareRootLogarithmic('not a number')).toThrow()
+ expect(() => squareRootLogarithmic(true)).toThrow()
+ })
+})