Exercise 18: Find Missing Numbers in Range

Problem Statement

Create a function `missingInRange(arr, start, end)` that returns missing numbers in range. Example: missingInRange([1, 3, 5], 1, 5) → [2, 4]

Sample Output:

missingInRange([1, 3, 5], 1, 5) => [2, 4]
missingInRange([1, 2, 3], 1, 5) => [4, 5]

Solution

const missingInRange = (arr, start, end) => {
  const set = new Set(arr);
  const missing = [];
  for (let i = start; i <= end; i++) if (!set.has(i)) missing.push(i);
  return missing;
};

Explanation

Overall Goal:

  • Range me missing numbers find karna.

Real world:

  • Data validation: missing IDs find.
  • Sequence analysis: gaps identify.