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What if we have the array sorted?
Loop the array and get the value A[i] then we need to find a value A[j] such that A[i] + A[j] < K which means A[j] < K - A[i]. In order to do that we can find that value with a binary search.
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Yes, variations of the Two Sum pattern are frequently asked in technical interviews, including FAANG-style companies. Problems like Two Sum Less Than K help evaluate understanding of sorting, two pointers, and efficient pair searching.
The problem primarily uses arrays and relies on techniques like sorting and two pointers. No advanced data structures are required, making it a good introductory problem for learning pointer-based strategies.
The most common optimal approach is to sort the array and then apply the two pointers technique. One pointer starts at the beginning and the other at the end, adjusting based on the current sum relative to k. This efficiently finds the maximum valid sum in O(n log n) time due to sorting.
Yes, after sorting the array you can iterate through each element and use binary search to find the largest partner value that keeps the sum less than k. This approach also runs in O(n log n) time and avoids checking all pairs.