From b7309f0018722801232f9de6219666e6ef69fd32 Mon Sep 17 00:00:00 2001
From: Omkarnath Parida <omkarnath.parida@yocket.in>
Date: Fri, 7 Oct 2022 20:36:47 +0530
Subject: [PATCH 01/12] =?UTF-8?q?=F0=9F=93=A6=20NEW:=20Added=20solution=20?=
 =?UTF-8?q?for=20ProjectEuler-007?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Project-Euler/Problem007.js           | 27 +++++++++++++++++++++++++++
 Project-Euler/test/Problem007.test.js | 17 +++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 Project-Euler/Problem007.js
 create mode 100644 Project-Euler/test/Problem007.test.js

diff --git a/Project-Euler/Problem007.js b/Project-Euler/Problem007.js
new file mode 100644
index 0000000000..48f27d56c1
--- /dev/null
+++ b/Project-Euler/Problem007.js
@@ -0,0 +1,27 @@
+import { PrimeCheck } from '../Maths/PrimeCheck.js'
+
+/**
+ * Find nth Prime Number
+ *
+ * P.S.(Project Euler - 007):
+ * By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.
+ * What is the 10001st prime number?
+ *
+ * @param {Number} n
+ * @returns {Number} returns the nth prime number
+ */
+export const nthPrime = (n) => {
+  if (n < 1) {
+    return 'Invalid Input'
+  }
+
+  let count = 0
+  let inc = 2
+  while (count < n) {
+    if (PrimeCheck(inc)) {
+      count++
+    }
+    inc++
+  }
+  return inc - 1
+}
diff --git a/Project-Euler/test/Problem007.test.js b/Project-Euler/test/Problem007.test.js
new file mode 100644
index 0000000000..e979e45728
--- /dev/null
+++ b/Project-Euler/test/Problem007.test.js
@@ -0,0 +1,17 @@
+import { nthPrime } from '../Problem007.js'
+
+describe('checking nth prime number', () => {
+  it('should be invalid input if number is negative', () => {
+    expect(nthPrime(-3)).toBe('Invalid Input')
+  })
+  it('should be invalid input if number is 0', () => {
+    expect(nthPrime(0)).toBe('Invalid Input')
+  })
+  test('if the number is greather than 0', () => {
+    expect(nthPrime(10)).toBe(29)
+  })
+  // Project Euler Condition Check
+  test('if the number is 10001', () => {
+    expect(nthPrime(10001)).toBe(104743)
+  })
+})

From d3a3b331c7d964262f524c37afb767c87994b6c3 Mon Sep 17 00:00:00 2001
From: Omkarnath Parida <omkarnath.parida@yocket.in>
Date: Fri, 7 Oct 2022 20:45:06 +0530
Subject: [PATCH 02/12] =?UTF-8?q?=F0=9F=90=9B=20FIX:=20Spelling=20mistake?=
 =?UTF-8?q?=20fixes?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Project-Euler/test/Problem007.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Project-Euler/test/Problem007.test.js b/Project-Euler/test/Problem007.test.js
index e979e45728..6c48f1e786 100644
--- a/Project-Euler/test/Problem007.test.js
+++ b/Project-Euler/test/Problem007.test.js
@@ -7,7 +7,7 @@ describe('checking nth prime number', () => {
   it('should be invalid input if number is 0', () => {
     expect(nthPrime(0)).toBe('Invalid Input')
   })
-  test('if the number is greather than 0', () => {
+  test('if the number is greater than 0', () => {
     expect(nthPrime(10)).toBe(29)
   })
   // Project Euler Condition Check

From e9b5a6a92174ff87a4d9b27cee8e596ad8fa76a3 Mon Sep 17 00:00:00 2001
From: Omkarnath Parida <omkarnath.parida@yocket.in>
Date: Fri, 7 Oct 2022 23:02:44 +0530
Subject: [PATCH 03/12] =?UTF-8?q?=F0=9F=91=8C=20IMPROVE:=20changed=20varia?=
 =?UTF-8?q?ble=20name=20from=20`inc`=20to=20`candidateValue`=20and=20throw?=
 =?UTF-8?q?n=20error=20in=20case=20of=20invalid=20input?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Project-Euler/Problem007.js           | 10 +++++-----
 Project-Euler/test/Problem007.test.js |  4 ++--
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/Project-Euler/Problem007.js b/Project-Euler/Problem007.js
index 48f27d56c1..95e3f10562 100644
--- a/Project-Euler/Problem007.js
+++ b/Project-Euler/Problem007.js
@@ -12,16 +12,16 @@ import { PrimeCheck } from '../Maths/PrimeCheck.js'
  */
 export const nthPrime = (n) => {
   if (n < 1) {
-    return 'Invalid Input'
+    throw new Error('Invalid Input')
   }
 
   let count = 0
-  let inc = 2
+  let candidateValue = 2
   while (count < n) {
-    if (PrimeCheck(inc)) {
+    if (PrimeCheck(candidateValue)) {
       count++
     }
-    inc++
+    candidateValue++
   }
-  return inc - 1
+  return candidateValue - 1
 }
diff --git a/Project-Euler/test/Problem007.test.js b/Project-Euler/test/Problem007.test.js
index 6c48f1e786..191d1e06af 100644
--- a/Project-Euler/test/Problem007.test.js
+++ b/Project-Euler/test/Problem007.test.js
@@ -2,10 +2,10 @@ import { nthPrime } from '../Problem007.js'
 
 describe('checking nth prime number', () => {
   it('should be invalid input if number is negative', () => {
-    expect(nthPrime(-3)).toBe('Invalid Input')
+    expect(() => nthPrime(-3)).toThrowError('Invalid Input')
   })
   it('should be invalid input if number is 0', () => {
-    expect(nthPrime(0)).toBe('Invalid Input')
+    expect(() => nthPrime(0)).toThrowError('Invalid Input')
   })
   test('if the number is greater than 0', () => {
     expect(nthPrime(10)).toBe(29)

From e99c7225579aa6da265352daa5140c037281c311 Mon Sep 17 00:00:00 2001
From: Omkarnath Parida <omkarnath.parida@yocket.in>
Date: Fri, 7 Oct 2022 23:23:09 +0530
Subject: [PATCH 04/12] =?UTF-8?q?=F0=9F=91=8C=20IMPROVE:=20Modified=20the?=
 =?UTF-8?q?=20code?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Project-Euler/Problem007.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Project-Euler/Problem007.js b/Project-Euler/Problem007.js
index 95e3f10562..009c1a896e 100644
--- a/Project-Euler/Problem007.js
+++ b/Project-Euler/Problem007.js
@@ -16,12 +16,12 @@ export const nthPrime = (n) => {
   }
 
   let count = 0
-  let candidateValue = 2
+  let candidateValue = 1
   while (count < n) {
+    candidateValue++
     if (PrimeCheck(candidateValue)) {
       count++
     }
-    candidateValue++
   }
-  return candidateValue - 1
+  return candidateValue
 }

From 0f9f1bab7decbea8a2fbfc06b4b8531a39d0d6e1 Mon Sep 17 00:00:00 2001
From: Omkarnath Parida <omkarnath.parida@yocket.in>
Date: Mon, 10 Oct 2022 19:50:16 +0530
Subject: [PATCH 05/12] =?UTF-8?q?=F0=9F=91=8C=20IMPROVE:=20Added=20test=20?=
 =?UTF-8?q?case=20for=20ProjectEuler=20Problem001?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Project-Euler/Problem001.js           |  4 +++-
 Project-Euler/test/Problem001.test.js | 17 +++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 Project-Euler/test/Problem001.test.js

diff --git a/Project-Euler/Problem001.js b/Project-Euler/Problem001.js
index 65a35e32a1..c47c10bd1c 100644
--- a/Project-Euler/Problem001.js
+++ b/Project-Euler/Problem001.js
@@ -5,9 +5,11 @@ Find the sum of all the multiples of 3 or 5 below the provided parameter value n
 */
 
 const multiplesThreeAndFive = (num) => {
+  if (num < 1) throw new Error('No natural numbers exist below 1')
+
   let total = 0
   // total for calculating the sum
-  for (let i = 0; i < num; i++) {
+  for (let i = 1; i < num; i++) {
     if (i % 3 === 0 || i % 5 === 0) {
       total += i
     }
diff --git a/Project-Euler/test/Problem001.test.js b/Project-Euler/test/Problem001.test.js
new file mode 100644
index 0000000000..e6b5549a57
--- /dev/null
+++ b/Project-Euler/test/Problem001.test.js
@@ -0,0 +1,17 @@
+import { multiplesThreeAndFive } from '../Problem001.js'
+
+describe('Sum of multiples of 3 or 5', () => {
+  it('should throw error when number is negative number', () => {
+    expect(() => multiplesThreeAndFive(-24)).toThrowError('No natural numbers exist below 1')
+  })
+  it('should throw error when number is 0', () => {
+    expect(() => multiplesThreeAndFive(0)).toThrowError('No natural numbers exist below 1')
+  })
+  test('if the number is greater than 0', () => {
+    expect(multiplesThreeAndFive(10)).toBe(23)
+  })
+  // Project Euler Condition Check
+  test('if the number is 1000', () => {
+    expect(multiplesThreeAndFive(1000)).toBe(233168)
+  })
+})

From b06c09b1ba7edb948af33b75ee9612972f79d9e3 Mon Sep 17 00:00:00 2001
From: Omkarnath Parida <omkarnath.parida@yocket.in>
Date: Sat, 15 Oct 2022 16:11:56 +0530
Subject: [PATCH 06/12] =?UTF-8?q?=F0=9F=93=A6=20NEW:=20Added=20solution=20?=
 =?UTF-8?q?for=20Project=20Euler-021?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Project-Euler/Problem021.js           | 45 +++++++++++++++++++++++++++
 Project-Euler/test/Problem021.test.js |  8 +++++
 2 files changed, 53 insertions(+)
 create mode 100644 Project-Euler/Problem021.js
 create mode 100644 Project-Euler/test/Problem021.test.js

diff --git a/Project-Euler/Problem021.js b/Project-Euler/Problem021.js
new file mode 100644
index 0000000000..45ff9e1552
--- /dev/null
+++ b/Project-Euler/Problem021.js
@@ -0,0 +1,45 @@
+/**
+ * Amicable numbers
+ *
+ * P.S.(Project Euler - 021):
+ * Let d(n) be defined as the sum of proper divisors of n (numbers less than n which divide evenly into n).
+ * If d(a) = b and d(b) = a, where a ≠ b, then a and b are an amicable pair and each of a and b are called amicable numbers.
+ *
+ * For example, the proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110;
+ * therefore d(220) = 284. The proper divisors of 284 are 1, 2, 4, 71 and 142; so d(284) = 220.
+ *
+ * Evaluate the sum of all the amicable numbers under 10000.
+ *
+ * @param {Number} maxNum
+ * @returns {Number} Sum of all amicable numbers under maxNum
+ */
+export const sumAmicableNum = (maxNum) => {
+  const amicNums = []
+
+  for (let i = 1; i < maxNum; i++) {
+    const left = d(i)
+    const right = d(left)
+    if (i === right && i !== left && amicNums.indexOf(i) === -1) {
+      amicNums.push(i, left)
+    }
+  }
+  return amicNums.reduce((a, b) => {
+    a += b
+    return a
+  })
+}
+
+const d = (num) => {
+  const output = []
+  for (let i = 1; i < num; i++) {
+    if (!(num % i)) { output.push(i) }
+  }
+  if (!output.length) {
+    return 0
+  } else {
+    return output.reduce((a, b) => {
+      a += b
+      return a
+    })
+  }
+}
diff --git a/Project-Euler/test/Problem021.test.js b/Project-Euler/test/Problem021.test.js
new file mode 100644
index 0000000000..fed82d362c
--- /dev/null
+++ b/Project-Euler/test/Problem021.test.js
@@ -0,0 +1,8 @@
+import { sumAmicableNum } from '../Problem021.js'
+
+describe('Amicable numbers', () => {
+  // Project Euler Condition Check
+  test('if the number is 10000', () => {
+    expect(sumAmicableNum(10000)).toBe(31626)
+  })
+})

From 959b0b62397f74b6851ee155d09dfc22e13b1dfe Mon Sep 17 00:00:00 2001
From: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Date: Sat, 15 Oct 2022 10:42:57 +0000
Subject: [PATCH 07/12] Updated Documentation in README.md

---
 DIRECTORY.md | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/DIRECTORY.md b/DIRECTORY.md
index 2eec03b7b6..c7fceb2d76 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -9,6 +9,7 @@
 * **Bit-Manipulation**
   * [BinaryCountSetBits](Bit-Manipulation/BinaryCountSetBits.js)
   * [IsPowerOfTwo](Bit-Manipulation/IsPowerOfTwo.js)
+  * [LogTwo](Bit-Manipulation/LogTwo.js)
   * [NextPowerOfTwo](Bit-Manipulation/NextPowerOfTwo.js)
   * [SetBit](Bit-Manipulation/SetBit.js)
 * **Cache**
@@ -20,7 +21,7 @@
 * **Ciphers**
   * [AffineCipher](Ciphers/AffineCipher.js)
   * [Atbash](Ciphers/Atbash.js)
-  * [CaesarsCipher](Ciphers/CaesarsCipher.js)
+  * [CaesarCipher](Ciphers/CaesarCipher.js)
   * [KeyFinder](Ciphers/KeyFinder.js)
   * [KeywordShiftedAlphabet](Ciphers/KeywordShiftedAlphabet.js)
   * [ROT13](Ciphers/ROT13.js)
@@ -68,7 +69,6 @@
     * [AddTwoNumbers](Data-Structures/Linked-List/AddTwoNumbers.js)
     * [CycleDetection](Data-Structures/Linked-List/CycleDetection.js)
     * [DoublyLinkedList](Data-Structures/Linked-List/DoublyLinkedList.js)
-    * [RotateListRight](Data-Structures/Linked-List/RotateListRight.js)
     * [SinglyCircularLinkedList](Data-Structures/Linked-List/SinglyCircularLinkedList.js)
     * [SinglyLinkedList](Data-Structures/Linked-List/SinglyLinkedList.js)
   * **Queue**
@@ -85,6 +85,7 @@
   * **Vectors**
     * [Vector2](Data-Structures/Vectors/Vector2.js)
 * **Dynamic-Programming**
+  * [CatalanNumbers](Dynamic-Programming/CatalanNumbers.js)
   * [ClimbingStairs](Dynamic-Programming/ClimbingStairs.js)
   * [CoinChange](Dynamic-Programming/CoinChange.js)
   * [EditDistance](Dynamic-Programming/EditDistance.js)
@@ -141,8 +142,10 @@
   * [BinaryConvert](Maths/BinaryConvert.js)
   * [BinaryExponentiationIterative](Maths/BinaryExponentiationIterative.js)
   * [BinaryExponentiationRecursive](Maths/BinaryExponentiationRecursive.js)
+  * [BinomialCoefficient](Maths/BinomialCoefficient.js)
   * [BisectionMethod](Maths/BisectionMethod.js)
   * [CheckKishnamurthyNumber](Maths/CheckKishnamurthyNumber.js)
+  * [CircularArc](Maths/CircularArc.js)
   * [CollatzSequence](Maths/CollatzSequence.js)
   * [Coordinate](Maths/Coordinate.js)
   * [CoPrimeCheck](Maths/CoPrimeCheck.js)
@@ -170,15 +173,18 @@
   * [IsEven](Maths/IsEven.js)
   * [IsOdd](Maths/IsOdd.js)
   * [IsPronic](Maths/IsPronic.js)
+  * [IsSquareFree](Maths/IsSquareFree.js)
   * [JugglerSequence](Maths/JugglerSequence.js)
   * [LeapYear](Maths/LeapYear.js)
   * [LinearSieve](Maths/LinearSieve.js)
+  * [LiouvilleFunction](Maths/LiouvilleFunction.js)
   * [LucasSeries](Maths/LucasSeries.js)
   * [Mandelbrot](Maths/Mandelbrot.js)
   * [MatrixExponentiationRecursive](Maths/MatrixExponentiationRecursive.js)
   * [MatrixMultiplication](Maths/MatrixMultiplication.js)
   * [MeanSquareError](Maths/MeanSquareError.js)
   * [MidpointIntegration](Maths/MidpointIntegration.js)
+  * [MobiusFunction](Maths/MobiusFunction.js)
   * [ModularBinaryExponentiationRecursive](Maths/ModularBinaryExponentiationRecursive.js)
   * [NumberOfDigits](Maths/NumberOfDigits.js)
   * [Palindrome](Maths/Palindrome.js)
@@ -216,6 +222,7 @@
   * [Problem004](Project-Euler/Problem004.js)
   * [Problem005](Project-Euler/Problem005.js)
   * [Problem006](Project-Euler/Problem006.js)
+  * [Problem007](Project-Euler/Problem007.js)
   * [Problem008](Project-Euler/Problem008.js)
   * [Problem009](Project-Euler/Problem009.js)
   * [Problem010](Project-Euler/Problem010.js)
@@ -225,6 +232,7 @@
   * [Problem016](Project-Euler/Problem016.js)
   * [Problem018](Project-Euler/Problem018.js)
   * [Problem020](Project-Euler/Problem020.js)
+  * [Problem021](Project-Euler/Problem021.js)
   * [Problem023](Project-Euler/Problem023.js)
   * [Problem025](Project-Euler/Problem025.js)
 * **Recursive**
@@ -245,6 +253,7 @@
   * [InterpolationSearch](Search/InterpolationSearch.js)
   * [JumpSearch](Search/JumpSearch.js)
   * [LinearSearch](Search/LinearSearch.js)
+  * [Minesweeper](Search/Minesweeper.js)
   * [QuickSelectSearch](Search/QuickSelectSearch.js)
   * [SlidingWindow](Search/SlidingWindow.js)
   * [StringSearch](Search/StringSearch.js)
@@ -296,6 +305,7 @@
   * [CheckRearrangePalindrome](String/CheckRearrangePalindrome.js)
   * [CheckSnakeCase](String/CheckSnakeCase.js)
   * [CheckWordOccurrence](String/CheckWordOccurrence.js)
+  * [CountSubstrings](String/CountSubstrings.js)
   * [CountVowels](String/CountVowels.js)
   * [CreatePermutations](String/CreatePermutations.js)
   * [DiceCoefficient](String/DiceCoefficient.js)

From 35ecee1526d0c1d3e3cdaab9c6402b02299b6b17 Mon Sep 17 00:00:00 2001
From: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Date: Sat, 15 Oct 2022 10:48:14 +0000
Subject: [PATCH 08/12] Updated Documentation in README.md

---
 DIRECTORY.md | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/DIRECTORY.md b/DIRECTORY.md
index 603a367734..e78a122fbc 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -2,7 +2,7 @@
   * [AllCombinationsOfSizeK](Backtracking/AllCombinationsOfSizeK.js)
   * [GeneratePermutations](Backtracking/GeneratePermutations.js)
   * [KnightTour](Backtracking/KnightTour.js)
-  * [NQueen](Backtracking/NQueen.js)
+  * [NQueens](Backtracking/NQueens.js)
   * [RatInAMaze](Backtracking/RatInAMaze.js)
   * [Sudoku](Backtracking/Sudoku.js)
   * [SumOfSubset](Backtracking/SumOfSubset.js)
@@ -149,6 +149,7 @@
   * [CollatzSequence](Maths/CollatzSequence.js)
   * [Coordinate](Maths/Coordinate.js)
   * [CoPrimeCheck](Maths/CoPrimeCheck.js)
+  * [CountNumbersDivisible](Maths/CountNumbersDivisible.js)
   * [DecimalExpansion](Maths/DecimalExpansion.js)
   * [DecimalIsolate](Maths/DecimalIsolate.js)
   * [DegreeToRadian](Maths/DegreeToRadian.js)
@@ -172,6 +173,7 @@
   * [IsDivisible](Maths/IsDivisible.js)
   * [IsEven](Maths/IsEven.js)
   * [IsOdd](Maths/IsOdd.js)
+  * [isPalindromeIntegerNumber](Maths/isPalindromeIntegerNumber.js)
   * [IsPronic](Maths/IsPronic.js)
   * [IsSquareFree](Maths/IsSquareFree.js)
   * [JugglerSequence](Maths/JugglerSequence.js)
@@ -227,6 +229,7 @@
   * [Problem008](Project-Euler/Problem008.js)
   * [Problem009](Project-Euler/Problem009.js)
   * [Problem010](Project-Euler/Problem010.js)
+  * [Problem011](Project-Euler/Problem011.js)
   * [Problem012](Project-Euler/Problem012.js)
   * [Problem013](Project-Euler/Problem013.js)
   * [Problem014](Project-Euler/Problem014.js)
@@ -238,6 +241,7 @@
   * [Problem021](Project-Euler/Problem021.js)
   * [Problem023](Project-Euler/Problem023.js)
   * [Problem025](Project-Euler/Problem025.js)
+  * [Problem044](Project-Euler/Problem044.js)
 * **Recursive**
   * [BinaryEquivalent](Recursive/BinaryEquivalent.js)
   * [BinarySearch](Recursive/BinarySearch.js)
@@ -291,6 +295,7 @@
   * [ShellSort](Sorts/ShellSort.js)
   * [SimplifiedWiggleSort](Sorts/SimplifiedWiggleSort.js)
   * [StoogeSort](Sorts/StoogeSort.js)
+  * [SwapSort](Sorts/SwapSort.js)
   * [TimSort](Sorts/TimSort.js)
   * [TopologicalSort](Sorts/TopologicalSort.js)
 * **String**

From d6eb962ee0f69b28a1d931c8eec7940091386f59 Mon Sep 17 00:00:00 2001
From: Omkarnath Parida <omkarnath.parida@yocket.in>
Date: Mon, 17 Oct 2022 23:08:28 +0530
Subject: [PATCH 09/12] =?UTF-8?q?=F0=9F=90=9B=20FIX:=20Some=20fixes?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Project-Euler/Problem021.js           | 18 ++++--------------
 Project-Euler/test/Problem021.test.js |  6 +++---
 2 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/Project-Euler/Problem021.js b/Project-Euler/Problem021.js
index 45ff9e1552..c97bacd3b0 100644
--- a/Project-Euler/Problem021.js
+++ b/Project-Euler/Problem021.js
@@ -13,7 +13,7 @@
  * @param {Number} maxNum
  * @returns {Number} Sum of all amicable numbers under maxNum
  */
-export const sumAmicableNum = (maxNum) => {
+export const sumAmicableNums = (maxNum) => {
   const amicNums = []
 
   for (let i = 1; i < maxNum; i++) {
@@ -23,23 +23,13 @@ export const sumAmicableNum = (maxNum) => {
       amicNums.push(i, left)
     }
   }
-  return amicNums.reduce((a, b) => {
-    a += b
-    return a
-  })
+  return amicNums.reduce((a, b) => a + b, 0)
 }
 
 const d = (num) => {
   const output = []
   for (let i = 1; i < num; i++) {
-    if (!(num % i)) { output.push(i) }
-  }
-  if (!output.length) {
-    return 0
-  } else {
-    return output.reduce((a, b) => {
-      a += b
-      return a
-    })
+    if (num % i === 0) { output.push(i) }
   }
+  return output.reduce((a, b) => a + b, 0)
 }
diff --git a/Project-Euler/test/Problem021.test.js b/Project-Euler/test/Problem021.test.js
index fed82d362c..f907c1553f 100644
--- a/Project-Euler/test/Problem021.test.js
+++ b/Project-Euler/test/Problem021.test.js
@@ -1,8 +1,8 @@
-import { sumAmicableNum } from '../Problem021.js'
+import { sumAmicableNums } from '../Problem021.js'
 
 describe('Amicable numbers', () => {
   // Project Euler Condition Check
-  test('if the number is 10000', () => {
-    expect(sumAmicableNum(10000)).toBe(31626)
+  test('if the limit is 10000', () => {
+    expect(sumAmicableNums(10000)).toBe(31626)
   })
 })

From 4017f5587b35c9bde537a6426d9342be15009907 Mon Sep 17 00:00:00 2001
From: Omkarnath Parida <omkarnath.parida@yocket.in>
Date: Sat, 15 Oct 2022 16:11:56 +0530
Subject: [PATCH 10/12] =?UTF-8?q?=F0=9F=93=A6=20NEW:=20Added=20solution=20?=
 =?UTF-8?q?for=20Project=20Euler-021?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Project-Euler/Problem021.js           | 45 +++++++++++++++++++++++++++
 Project-Euler/test/Problem021.test.js |  8 +++++
 2 files changed, 53 insertions(+)
 create mode 100644 Project-Euler/Problem021.js
 create mode 100644 Project-Euler/test/Problem021.test.js

diff --git a/Project-Euler/Problem021.js b/Project-Euler/Problem021.js
new file mode 100644
index 0000000000..45ff9e1552
--- /dev/null
+++ b/Project-Euler/Problem021.js
@@ -0,0 +1,45 @@
+/**
+ * Amicable numbers
+ *
+ * P.S.(Project Euler - 021):
+ * Let d(n) be defined as the sum of proper divisors of n (numbers less than n which divide evenly into n).
+ * If d(a) = b and d(b) = a, where a ≠ b, then a and b are an amicable pair and each of a and b are called amicable numbers.
+ *
+ * For example, the proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110;
+ * therefore d(220) = 284. The proper divisors of 284 are 1, 2, 4, 71 and 142; so d(284) = 220.
+ *
+ * Evaluate the sum of all the amicable numbers under 10000.
+ *
+ * @param {Number} maxNum
+ * @returns {Number} Sum of all amicable numbers under maxNum
+ */
+export const sumAmicableNum = (maxNum) => {
+  const amicNums = []
+
+  for (let i = 1; i < maxNum; i++) {
+    const left = d(i)
+    const right = d(left)
+    if (i === right && i !== left && amicNums.indexOf(i) === -1) {
+      amicNums.push(i, left)
+    }
+  }
+  return amicNums.reduce((a, b) => {
+    a += b
+    return a
+  })
+}
+
+const d = (num) => {
+  const output = []
+  for (let i = 1; i < num; i++) {
+    if (!(num % i)) { output.push(i) }
+  }
+  if (!output.length) {
+    return 0
+  } else {
+    return output.reduce((a, b) => {
+      a += b
+      return a
+    })
+  }
+}
diff --git a/Project-Euler/test/Problem021.test.js b/Project-Euler/test/Problem021.test.js
new file mode 100644
index 0000000000..fed82d362c
--- /dev/null
+++ b/Project-Euler/test/Problem021.test.js
@@ -0,0 +1,8 @@
+import { sumAmicableNum } from '../Problem021.js'
+
+describe('Amicable numbers', () => {
+  // Project Euler Condition Check
+  test('if the number is 10000', () => {
+    expect(sumAmicableNum(10000)).toBe(31626)
+  })
+})

From a33da9aa724b9b38a70ef380cb890842cf683544 Mon Sep 17 00:00:00 2001
From: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Date: Sat, 15 Oct 2022 10:42:57 +0000
Subject: [PATCH 11/12] Updated Documentation in README.md

---
 DIRECTORY.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/DIRECTORY.md b/DIRECTORY.md
index e1bbd77000..c86cccec18 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -239,6 +239,7 @@
   * [Problem017](Project-Euler/Problem017.js)
   * [Problem018](Project-Euler/Problem018.js)
   * [Problem020](Project-Euler/Problem020.js)
+  * [Problem021](Project-Euler/Problem021.js)
   * [Problem023](Project-Euler/Problem023.js)
   * [Problem025](Project-Euler/Problem025.js)
   * [Problem028](Project-Euler/Problem028.js)

From 7fd38e6b128943029980b8b16c7887f068038b3e Mon Sep 17 00:00:00 2001
From: Omkarnath Parida <omkarnath.parida@yocket.in>
Date: Mon, 17 Oct 2022 23:08:28 +0530
Subject: [PATCH 12/12] =?UTF-8?q?=F0=9F=90=9B=20FIX:=20Some=20fixes?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 Project-Euler/Problem021.js           | 18 ++++--------------
 Project-Euler/test/Problem021.test.js |  6 +++---
 2 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/Project-Euler/Problem021.js b/Project-Euler/Problem021.js
index 45ff9e1552..c97bacd3b0 100644
--- a/Project-Euler/Problem021.js
+++ b/Project-Euler/Problem021.js
@@ -13,7 +13,7 @@
  * @param {Number} maxNum
  * @returns {Number} Sum of all amicable numbers under maxNum
  */
-export const sumAmicableNum = (maxNum) => {
+export const sumAmicableNums = (maxNum) => {
   const amicNums = []
 
   for (let i = 1; i < maxNum; i++) {
@@ -23,23 +23,13 @@ export const sumAmicableNum = (maxNum) => {
       amicNums.push(i, left)
     }
   }
-  return amicNums.reduce((a, b) => {
-    a += b
-    return a
-  })
+  return amicNums.reduce((a, b) => a + b, 0)
 }
 
 const d = (num) => {
   const output = []
   for (let i = 1; i < num; i++) {
-    if (!(num % i)) { output.push(i) }
-  }
-  if (!output.length) {
-    return 0
-  } else {
-    return output.reduce((a, b) => {
-      a += b
-      return a
-    })
+    if (num % i === 0) { output.push(i) }
   }
+  return output.reduce((a, b) => a + b, 0)
 }
diff --git a/Project-Euler/test/Problem021.test.js b/Project-Euler/test/Problem021.test.js
index fed82d362c..f907c1553f 100644
--- a/Project-Euler/test/Problem021.test.js
+++ b/Project-Euler/test/Problem021.test.js
@@ -1,8 +1,8 @@
-import { sumAmicableNum } from '../Problem021.js'
+import { sumAmicableNums } from '../Problem021.js'
 
 describe('Amicable numbers', () => {
   // Project Euler Condition Check
-  test('if the number is 10000', () => {
-    expect(sumAmicableNum(10000)).toBe(31626)
+  test('if the limit is 10000', () => {
+    expect(sumAmicableNums(10000)).toBe(31626)
   })
 })