Add countNumbersDivisible algorithm with improved logic

Author: AdvikHegde

src/Math/countNumbersDivisible.js

@@ -0,0 +1,56 @@
+/**
+ * Count the numbers divisible by ‘M’ in a given range
+ *
+ * @see {@link https://www.tutorialspoint.com/count-the-numbers-divisible-by-m-in-a-given-range-in-cplusplus}
+ *
+ * We have 3 numbers A, B, M as inputs, A and B defines the numbers range [A, B]
+ * Count the total number of divisibles in that range by number M
+ *
+ * @author Chetan07j
+ */
+
+/**
+ * Function to find total divisibles in given range
+ *
+ * @param {number} num1
+ * @param {number} num2
+ * @param {number} divider
+ *
+ * @returns {number} count of total number of divisibles
+ */
+const countNumbersDivisible = (num1, num2, divider) => {
+  if (
+    typeof num1 !== 'number' ||
+    typeof num2 !== 'number' ||
+    typeof divider !== 'number'
+  ) {
+    throw new Error('Invalid input, please pass only numbers')
+  }
+
+  // Valid number range is num1 < num2, otherwise throw error
+  if (num1 > num2) {
+    throw new Error(
+      'Invalid number range, please provide numbers such that num1 < num2'
+    )
+  }
+
+  // if divider is out of range then return 0
+  // as in such case no divisible exists
+  if (divider > num2) {
+    return 0
+  }
+
+  // Divider cannot be zero, as division by zero is invalid
+  if (divider === 0) {
+    throw new Error('Divider cannot be zero')
+  }
+
+  // Find the number of multiples of divider for num1 and num2
+  // using integer division for accurate counting
+  const divisibleCount =
+    Math.floor(num2 / divider) - Math.floor((num1 - 1) / divider)
+
+  return divisibleCount
+}
+
+export { countNumbersDivisible }