Add tests to Math (TheAlgorithms#423)

* Add prettier config

* test: add test to check for absolute function

* chore: es5 to es6

* test: add test to check mean function

* test: add test for sum of digit

* test: add test for factorial

* test: add test for fibonnaci

* test: add test for find HCF

* test: add test for lcm

* test: add gridget test

* test: add test for mean square error

* test: add test for modular binary exponentiation

* test: add tests for palindrome

* test: add test for pascals triangle

* test: add tests for polynomial

* test: add tests for prime check

* test: add tests for reverse polish notation

* test: add tests for sieve of eratosthenes

* test: add tests for pi estimation monte carlo method

* chore: move tests to test folder

* chore: fix standardjs errors

Author: ephraimduncan

.prettierrc

@@ -0,0 +1,15 @@
+{
+  "arrowParens": "always",
+  "bracketSpacing": true,
+  "endOfLine": "lf",
+  "insertPragma": false,
+  "printWidth": 80,
+  "proseWrap": "preserve",
+  "quoteProps": "as-needed",
+  "requirePragma": false,
+  "semi": false,
+  "singleQuote": true,
+  "tabWidth": 2,
+  "trailingComma": "none",
+  "useTabs": false
+}

Maths/Abs.js

@@ -11,7 +11,7 @@
         https://en.wikipedia.org/wiki/Absolute_value
 */
 
-function absVal (num) {
+const absVal = (num) => {
   // Find absolute value of `num`.
   'use strict'
   if (num < 0) {
@@ -21,6 +21,4 @@ function absVal (num) {
   return num
 }
 
-// Run `abs` function to find absolute value of two numbers.
-console.log('The absolute value of -34 is ' + absVal(-34))
-console.log('The absolute value of 34 is ' + absVal(34))
+export { absVal }

Maths/AverageMean.js

@@ -14,18 +14,16 @@
 
 const mean = (nums) => {
   // This is a function returns average/mean of array
-  var sum = 0
-  var avg
+  let sum = 0
 
   // This loop sums all values in the 'nums' array using forEach loop
   nums.forEach(function (current) {
     sum += current
   })
 
   // Divide sum by the length of the 'nums' array.
-  avg = sum / nums.length
+  const avg = sum / nums.length
   return avg
 }
 
-// Run `mean` Function to find average of a list of numbers.
-console.log(mean([2, 4, 6, 8, 20, 50, 70]))
+export { mean }

Maths/digitSum.js renamed to Maths/DigitSum.js

@@ -1,18 +1,16 @@
 // program to find sum of digits of a number
 
 // function which would calculate sum and return it
-function digitSum (num) {
+const digitSum = (num) => {
   // sum will store sum of digits of a number
   let sum = 0
   // while will run untill num become 0
   while (num) {
-    sum += (num % 10)
+    sum += num % 10
     num = parseInt(num / 10)
   }
 
   return sum
 }
 
-// assigning number
-const num = 12345
-console.log(digitSum(num))
+export { digitSum }

Maths/Factorial.js

@@ -13,20 +13,20 @@
 
 'use strict'
 
-function calcRange (num) {
+const calcRange = (num) => {
   // Generate a range of numbers from 1 to `num`.
-  var i = 1
-  var range = []
+  let i = 1
+  const range = []
   while (i <= num) {
     range.push(i)
     i += 1
   }
   return range
 }
 
-function calcFactorial (num) {
-  var factorial
-  var range = calcRange(num)
+const calcFactorial = (num) => {
+  let factorial
+  const range = calcRange(num)
 
   // Check if the number is negative, positive, null, undefined, or zero
   if (num < 0) {
@@ -43,11 +43,8 @@ function calcFactorial (num) {
     range.forEach(function (i) {
       factorial = factorial * i
     })
-    return 'The factorial of ' + num + ' is ' + factorial
+    return `The factorial of ${num} is ${factorial}`
   }
 }
 
-// Run `factorial` Function to find average of a list of numbers.
-
-var num = console.log('Enter a number: ')
-console.log(calcFactorial(num))
+export { calcFactorial }

Maths/Fibonacci.js

@@ -66,18 +66,10 @@ const FibonacciDpWithoutRecursion = (number) => {
   for (var i = 2; i < number; ++i) {
     table.push(table[i - 1] + table[i - 2])
   }
-  return (table)
+  return table
 }
 
-// testing
-
-console.log(FibonacciIterative(5))
-// Output: [ 1, 1, 2, 3, 5 ]
-console.log(FibonacciRecursive(5))
-// Output: [ 1, 1, 2, 3, 5 ]
-
-console.log(FibonacciRecursiveDP(5))
-// Output: 5
-
-console.log(FibonacciDpWithoutRecursion(5))
-// Output: [ 1, 1, 2, 3, 5 ]
+export { FibonacciDpWithoutRecursion }
+export { FibonacciIterative }
+export { FibonacciRecursive }
+export { FibonacciRecursiveDP }

Maths/FindHcf.js

@@ -4,7 +4,7 @@
         https://en.wikipedia.org/wiki/Greatest_common_divisor
  */
 
-function findHCF (x, y) {
+const findHCF = (x, y) => {
   // If the input numbers are less than 1 return an error message.
   if (x < 1 || y < 1) {
     return 'Please enter values greater than zero.'
@@ -27,4 +27,5 @@ function findHCF (x, y) {
   // When the while loop finishes the minimum of x and y is the HCF.
   return Math.min(x, y)
 }
-console.log(findHCF(27, 36))
+
+export { findHCF }

Maths/FindLcm.js

@@ -12,9 +12,19 @@
 'use strict'
 
 // Find the LCM of two numbers.
-function findLcm (num1, num2) {
-  var maxNum
-  var lcm
+const findLcm = (num1, num2) => {
+  // If the input numbers are less than 1 return an error message.
+  if (num1 < 1 || num2 < 1) {
+    return 'Please enter values greater than zero.'
+  }
+
+  // If the input numbers are not integers return an error message.
+  if (num1 !== Math.round(num1) || num2 !== Math.round(num2)) {
+    return 'Please enter whole numbers.'
+  }
+
+  let maxNum
+  let lcm
   // Check to see whether num1 or num2 is larger.
   if (num1 > num2) {
     maxNum = num1
@@ -24,15 +34,10 @@ function findLcm (num1, num2) {
   lcm = maxNum
 
   while (true) {
-    if ((lcm % num1 === 0) && (lcm % num2 === 0)) {
-      break
-    }
+    if (lcm % num1 === 0 && lcm % num2 === 0) break
     lcm += maxNum
   }
   return lcm
 }
 
-// Run `findLcm` Function
-var num1 = 12
-var num2 = 76
-console.log(findLcm(num1, num2))
+export { findLcm }

Maths/GridGet.js

@@ -40,17 +40,14 @@
 */
 
 const gridGetX = (columns, index) => {
-  while ((index + 1) > columns) {
+  while (index + 1 > columns) {
     index = index - columns
   }
-  return (index + 1)
+  return index + 1
 }
 
 const gridGetY = (columns, index) => {
-  return (Math.floor(index / columns)) + 1
+  return Math.floor(index / columns) + 1
 }
 
-console.log(`If a square array has 400 elements,  then the value of x for the 27th element is ${gridGetX(Math.sqrt(400), 27)}`)
-console.log(`If an array has 7 columns and 3 rows,  then the value of x for the 11th element is ${gridGetX(7, 11)}`)
-console.log(`If a square array has 400 elements,  then the value of y for the 27th element is ${gridGetY(Math.sqrt(400), 27)}`)
-console.log(`If an array has 7 columns and 3 rows,  then the value of y for the 11th element is ${gridGetY(7, 11)}`)
+export { gridGetX, gridGetY }

Maths/MeanSquareError.js

@@ -18,9 +18,4 @@ const meanSquaredError = (predicted, expected) => {
   return err / expected.length
 }
 
-// testing
-(() => {
-  console.log(meanSquaredError([1, 2, 3, 4], [1, 2, 3, 4]) === 0)
-  console.log(meanSquaredError([4, 3, 2, 1], [1, 2, 3, 4]) === 5)
-  console.log(meanSquaredError([2, 0, 2, 0], [0, 0, 0, 0]) === 3)
-})()
+export { meanSquaredError }

Maths/ModularBinaryExponentiationRecursive.js

@@ -19,13 +19,4 @@ const modularBinaryExponentiation = (a, n, m) => {
   }
 }
 
-const main = () => {
-  // binary_exponentiation(2, 10, 17)
-  // > 4
-  console.log(modularBinaryExponentiation(2, 10, 17))
-  // binary_exponentiation(3, 9, 12)
-  // > 3
-  console.log(modularBinaryExponentiation(3, 9, 12))
-}
-
-main()
+export { modularBinaryExponentiation }

Maths/Palindrome.js

@@ -14,7 +14,7 @@
  * @complexity: O(n)
  */
 
-function PalindromeRecursive (string) {
+const PalindromeRecursive = (string) => {
   // Base case
   if (string.length < 2) return true
 
@@ -26,7 +26,7 @@ function PalindromeRecursive (string) {
   return PalindromeRecursive(string.slice(1, string.length - 1))
 }
 
-function PalindromeIterative (string) {
+const PalindromeIterative = (string) => {
   const _string = string
     .toLowerCase()
     .replace(/ /g, '')
@@ -45,7 +45,4 @@ function PalindromeIterative (string) {
   return true
 }
 
-// testing
-
-console.log(PalindromeRecursive('Javascript Community'))
-console.log(PalindromeIterative('mom'))
+export { PalindromeIterative, PalindromeRecursive }

Maths/PascalTriangle.js

@@ -1,6 +1,16 @@
-const numRows = 5
+const addRow = (triangle) => {
+  const previous = triangle[triangle.length - 1]
+  const newRow = [1]
+  for (let i = 0; i < previous.length - 1; i++) {
+    const current = previous[i]
+    const next = previous[i + 1]
+    newRow.push(current + next)
+  }
+  newRow.push(1)
+  return triangle.push(newRow)
+}
 
-var generate = function (numRows) {
+const generate = (numRows) => {
   const triangle = [[1], [1, 1]]
 
   if (numRows === 0) {
@@ -16,16 +26,5 @@ var generate = function (numRows) {
   }
   return triangle
 }
-var addRow = function (triangle) {
-  const previous = triangle[triangle.length - 1]
-  const newRow = [1]
-  for (let i = 0; i < previous.length - 1; i++) {
-    const current = previous[i]
-    const next = previous[i + 1]
-    newRow.push(current + next)
-  }
-  newRow.push(1)
-  return triangle.push(newRow)
-}
 
-generate(numRows)
+export { generate }

Maths/PiApproximationMonteCarlo.js

@@ -1,7 +1,7 @@
 // Wikipedia: https://en.wikipedia.org/wiki/Monte_Carlo_method
 // Video Explaination: https://www.youtube.com/watch?v=ELetCV_wX_c
 
-function piEstimation (iterations = 100000) {
+const piEstimation = (iterations = 100000) => {
   let circleCounter = 0
 
   for (let i = 0; i < iterations; i++) {
@@ -18,8 +18,4 @@ function piEstimation (iterations = 100000) {
   return pi
 }
 
-function main () {
-  console.log(piEstimation())
-}
-
-main()
+export { piEstimation }

Maths/Polynomial.js

@@ -1,4 +1,3 @@
-
 /**
  * Polynomials are algebraic expressions consisting of two or more algebraic terms.
  * Terms of a polynomial are:
@@ -20,18 +19,19 @@ class Polynomial {
    * Function to construct the polynomial in terms of x using the coefficientArray
    */
   construct () {
-    this.polynomial = this.coefficientArray.map((coefficient, exponent) => {
-      if (coefficient === 0) {
-        return '0'
-      }
-      if (exponent === 0) {
-        return `(${coefficient})`
-      } else if (exponent === 1) {
-        return `(${coefficient}x)`
-      } else {
-        return `(${coefficient}x^${exponent})`
-      }
-    })
+    this.polynomial = this.coefficientArray
+      .map((coefficient, exponent) => {
+        if (coefficient === 0) {
+          return '0'
+        }
+        if (exponent === 0) {
+          return `(${coefficient})`
+        } else if (exponent === 1) {
+          return `(${coefficient}x)`
+        } else {
+          return `(${coefficient}x^${exponent})`
+        }
+      })
       .filter((x) => {
         if (x !== '0') {
           return x
@@ -55,28 +55,9 @@ class Polynomial {
    */
   evaluate (value) {
     return this.coefficientArray.reduce((result, coefficient, exponent) => {
-      return result + coefficient * (Math.pow(value, exponent))
+      return result + coefficient * Math.pow(value, exponent)
     }, 0)
   }
 }
 
-/**
- * Function to perform tests
- */
-const tests = () => {
-  const polynomialOne = new Polynomial([1, 2, 3, 4])
-  console.log('Test 1: [1,2,3,4]')
-  console.log('Display Polynomial ', polynomialOne.display())
-  // (4x^3) + (3x^2) + (2x) + (1)
-  console.log('Evaluate Polynomial value=2 ', polynomialOne.evaluate(2))
-  // 49
-
-  const polynomialTwo = new Polynomial([5, 0, 0, -4, 3])
-  console.log('Test 2: [5,0,0,-4,3]')
-  console.log('Display Polynomial ', polynomialTwo.display())
-  // (3x^4) + (-4x^3) + (5)
-  console.log('Evaluate Polynomial value=1 ', polynomialTwo.evaluate(1))
-  // 4
-}
-
-tests()
+export { Polynomial }