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Classic binary search plus two-pointer setup.
Use binary search to find the insertion point of the target, then use two pointers to expand outward and collect the k closest elements. Alternatively, use a sliding window of size k and move it to minimize the distance to the target. Discuss time and space complexity and handle edge cases like duplicates and ties.
Pro tip: Clarify tie-breaking rules (e.g., prefer smaller elements when distances are equal) and mention that the array is sorted, so binary search is optimal. Also, consider if k is larger than the array size and handle that gracefully.
Ask about tie-breaking, whether the result should be sorted, and constraints like k > array length. Confirm the array is sorted and contains integers.
Decide between binary search + two pointers or sliding window. Explain why binary search is efficient for sorted arrays, achieving O(log n + k) time.
Write code to find the closest elements. For binary search, find the insertion point, then compare distances from left and right pointers, adding the closer element to the result until k elements are collected.
State time and space complexity. Walk through examples, including edge cases like target smaller than all elements, larger than all, and duplicates.
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