You are given an array of integers and a threshold value k. In one operation, you can remove any element from the array that is less than k. The goal is to find the minimum number of operations required so that every remaining element in the array is greater than or equal to k.
This Easy-level problem is typically used in initial screening rounds or at firms like TCS to test basic understanding of array filtering and counting. It's a straightforward assessment of a candidate's ability to iterate through data and apply a simple conditional count.
The algorithmic pattern is a simple Linear Scan. You iterate through the array once and count how many elements are strictly less than k. Each such element must be removed to satisfy the condition, so the count is your answer.
[2, 11, 10, 1, 3], k = 10Even in simple problems, mistakes happen. Some candidates might use a sorting-based approach (O(n log n)), which is unnecessary since a single pass (O(n)) is sufficient. Others might misread "greater than or equal to" as "strictly greater than," leading to an off-by-one error in the final count.
For "Easy" problems, focus on writing the most concise and efficient code possible. Always double-check the comparison operators (< vs <=) and ensure you handle edge cases like an empty array or an array where all elements already meet the threshold.