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$ curl repovive.com/roadmaps/fundamental-algorithms/sliding-window/fixed-size-window

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$ curl repovive.com/roadmaps/fundamental-algorithms/sliding-window/fixed-size-window

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Fixed-Size Window - Sliding Window | Fundamental Algorithms | Repovive

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Fundamental Algorithms8 sections · 294 units2h total

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Fixed-Size Window

Windows of constant length k.

Fixed window of size $k$ slides across array, updating a running value.

Max sum of $k$ elements:

function maxSumSubarray(arr, k):
    windowSum = sum of arr[0..k-1]
    maxSum = windowSum
    for i from k to n-1:
        windowSum = windowSum + arr[i] - arr[i-k]
        maxSum = max(maxSum, windowSum)
    return maxSum

Add entering element, remove leaving. $O(1)$ update.

Time: $O(n)$ . Space: $O(1)$ .