solution: ProjectEuler-007 (#1142)

* 📦 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

Co-authored-by: Omkarnath Parida <omkarnath.parida@yocket.in>

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) {
+    throw new Error('Invalid Input')
+  }
+
+  let count = 0
+  let candidateValue = 1
+  while (count < n) {
+    candidateValue++
+    if (PrimeCheck(candidateValue)) {
+      count++
+    }
+  }
+  return candidateValue
+}

Project-Euler/test/Problem007.test.js

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+import { nthPrime } from '../Problem007.js'
+
+describe('checking nth prime number', () => {
+  it('should be invalid input if number is negative', () => {
+    expect(() => nthPrime(-3)).toThrowError('Invalid Input')
+  })
+  it('should be invalid input if number is 0', () => {
+    expect(() => nthPrime(0)).toThrowError('Invalid Input')
+  })
+  test('if the number is greater than 0', () => {
+    expect(nthPrime(10)).toBe(29)
+  })
+  // Project Euler Condition Check
+  test('if the number is 10001', () => {
+    expect(nthPrime(10001)).toBe(104743)
+  })
+})