From ee52fb63af7591cfb9ef7222fd193f8f5ae571f6 Mon Sep 17 00:00:00 2001
From: sarthakgupta1907-cell <sarthakgupta1907@gmail.com>
Date: Sat, 7 Nov 2026 02:05:30 +0530
Subject: [PATCH] feat: add pronic number algorithm

---
 Maths/PronicNumber.js           | 21 ++++++++++++++
 Maths/test/PronicNumber.test.js | 51 +++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 Maths/PronicNumber.js
 create mode 100644 Maths/test/PronicNumber.test.js

diff --git a/Maths/PronicNumber.js b/Maths/PronicNumber.js
new file mode 100644
index 0000000000..7d6121e8f6
--- /dev/null
+++ b/Maths/PronicNumber.js
@@ -0,0 +1,21 @@
+/**
+ * @function isPronicNumber
+ * @description A pronic number (also known as an oblong number) is a
+ *   number that is the product of two consecutive integers.
+ *   Examples: 0, 2, 6, 12, 20, 30, 42...
+ * @param {number} n - A non-negative integer
+ * @returns {boolean} - True if n is a pronic number, false otherwise
+ * @see https://en.wikipedia.org/wiki/Pronic_number
+ * @example isPronicNumber(6) => true
+ * @example isPronicNumber(12) => true
+ * @example isPronicNumber(10) => false
+ */
+const isPronicNumber = (n) => {
+  if (!Number.isInteger(n) || n < 0) {
+    throw new TypeError('Input must be a non-negative integer')
+  }
+  const sqrt = Math.floor(Math.sqrt(n))
+  return sqrt * (sqrt + 1) === n
+}
+
+export { isPronicNumber }
diff --git a/Maths/test/PronicNumber.test.js b/Maths/test/PronicNumber.test.js
new file mode 100644
index 0000000000..869935e90e
--- /dev/null
+++ b/Maths/test/PronicNumber.test.js
@@ -0,0 +1,51 @@
+import { isPronicNumber } from '../PronicNumber.js'
+
+describe('isPronicNumber', () => {
+  test('0 is a pronic number (0 x 1)', () => {
+    expect(isPronicNumber(0)).toBe(true)
+  })
+
+  test('2 is a pronic number (1 x 2)', () => {
+    expect(isPronicNumber(2)).toBe(true)
+  })
+
+  test('6 is a pronic number (2 x 3)', () => {
+    expect(isPronicNumber(6)).toBe(true)
+  })
+
+  test('12 is a pronic number (3 x 4)', () => {
+    expect(isPronicNumber(12)).toBe(true)
+  })
+
+  test('20 is a pronic number (4 x 5)', () => {
+    expect(isPronicNumber(20)).toBe(true)
+  })
+
+  test('30 is a pronic number (5 x 6)', () => {
+    expect(isPronicNumber(30)).toBe(true)
+  })
+
+  test('42 is a pronic number (6 x 7)', () => {
+    expect(isPronicNumber(42)).toBe(true)
+  })
+
+  test('1 is NOT a pronic number', () => {
+    expect(isPronicNumber(1)).toBe(false)
+  })
+
+  test('10 is NOT a pronic number', () => {
+    expect(isPronicNumber(10)).toBe(false)
+  })
+
+  test('15 is NOT a pronic number', () => {
+    expect(isPronicNumber(15)).toBe(false)
+  })
+
+  test('throws TypeError for negative input', () => {
+    expect(() => isPronicNumber(-1)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for float input', () => {
+    expect(() => isPronicNumber(6.5)).toThrow(TypeError)
+  })
+})