Maintain a window of fixed or variable size that slides across an array. Add the new element on the right and remove the old element on the left — no need to recompute the full sum.
time:O(n)
space:O(1)
⚡ +100_XP
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> Start
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▸Find maximum sum subarray of size k=3. Sliding window avoids recomputing the whole sum each time.
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