prettier fixes & added test cases for Project Euler problem 4 (TheAlgorithms#1566)

* 📦 NEW: Added solution for ProjectEuler-007

* 🐛 FIX: Spelling mistake fixes

* 👌 IMPROVE: changed variable name from `inc` to `candidateValue` and thrown error in case of invalid input

* 👌 IMPROVE: Modified the code

* 👌 IMPROVE: Added test case for ProjectEuler Problem001

* 👌 IMPROVE: Added test cases for Project Euler Problem 4

* 👌 IMPROVE: auto prettier fixes

---------

Co-authored-by: Omkarnath Parida <[email protected]>

Author: pomkarnath98

Bit-Manipulation/BinaryCountSetBits.js

@@ -16,7 +16,7 @@ function BinaryCountSetBits(a) {
 
   let count = 0
   while (a) {
-    a &= (a - 1)
+    a &= a - 1
     count++
   }
 

Maths/AutomorphicNumber.js

@@ -35,6 +35,6 @@ export const isAutomorphic = (n) => {
     n = Math.floor(n / 10)
     n_sq = Math.floor(n_sq / 10)
   }
-  
+
   return true
 }

Maths/test/AutomorphicNumber.test.js

@@ -9,19 +9,19 @@ describe('AutomorphicNumber', () => {
   })
 
   test.each([
-    { n: -3 , expected: false },
-    { n: -25 , expected: false },
+    { n: -3, expected: false },
+    { n: -25, expected: false }
   ])('should return false when n is negetive', ({ n, expected }) => {
     expect(isAutomorphic(n)).toBe(false)
   })
 
   test.each([
-    { n: 7 , expected: false },
-    { n: 83 , expected: false },
-    { n: 0 , expected: true },
-    { n: 1 , expected: true },
-    { n: 376 , expected: true },
-    { n: 90625 , expected: true },
+    { n: 7, expected: false },
+    { n: 83, expected: false },
+    { n: 0, expected: true },
+    { n: 1, expected: true },
+    { n: 376, expected: true },
+    { n: 90625, expected: true }
   ])('should return $expected when n is $n', ({ n, expected }) => {
     expect(isAutomorphic(n)).toBe(expected)
   })

Project-Euler/Problem006.js

@@ -1,8 +1,8 @@
 // https://projecteuler.net/problem=6
 
 export const squareDifference = (num = 100) => {
-  let sumOfSquares = (num)*(num+1)*(2*num+1)/6
-  let sums = (num*(num+1))/2
-  
+  let sumOfSquares = (num * (num + 1) * (2 * num + 1)) / 6
+  let sums = (num * (num + 1)) / 2
+
   return sums ** 2 - sumOfSquares // difference of square of the total sum and sum of squares
 }

Project-Euler/test/Problem004.test.js

@@ -0,0 +1,11 @@
+import { largestPalindromic } from '../Problem004.js'
+
+describe('Largest Palindromic Number', () => {
+  test('if digit is 2', () => {
+    expect(largestPalindromic(2)).toBe(9009)
+  })
+  // Project Euler Condition Check
+  test('if digit is 3', () => {
+    expect(largestPalindromic(3)).toBe(906609)
+  })
+})

Recursive/test/BinaryEquivalent.test.js

@@ -1,29 +1,29 @@
-import { binaryEquivalent } from "../BinaryEquivalent";
+import { binaryEquivalent } from '../BinaryEquivalent'
 
 const tests = [
-    {
-        test: 2,
-        expectedValue: "10"
-    },
-    {       
-        test: 0,
-        expectedValue: "0"
-    },
-    {
-        test: 543,
-        expectedValue: "1000011111"
-    },
-    {
-        test: 4697621023,
-        expectedValue: "100011000000000000000001000011111"
-    }
+  {
+    test: 2,
+    expectedValue: '10'
+  },
+  {
+    test: 0,
+    expectedValue: '0'
+  },
+  {
+    test: 543,
+    expectedValue: '1000011111'
+  },
+  {
+    test: 4697621023,
+    expectedValue: '100011000000000000000001000011111'
+  }
 ]
 
-describe("Binary Equivalent", () => {
-    test.each(tests)(
-        "of $test should be $expectedValue",
-        ({test, expectedValue}) => {
-            expect(binaryEquivalent(test)).toBe(expectedValue);
-        }
-    )
+describe('Binary Equivalent', () => {
+  test.each(tests)(
+    'of $test should be $expectedValue',
+    ({ test, expectedValue }) => {
+      expect(binaryEquivalent(test)).toBe(expectedValue)
+    }
+  )
 })

Search/InterpolationSearch.js

@@ -36,4 +36,4 @@ export function interpolationSearch(arr, key) {
   }
 
   return -1
-}
+}