Sliding Window

The Sliding Window Technique is a method used to efficiently solve problems that involve processing subarrays or substrings within a larger sequence.

It operates by maintaining a window with either a static or a dynamic size, depending on the requirements of the problem.

The advantage of keeping such window is that we can drop the time complexity from $O(n^2)$ to $O(n)$. In fact, a typical brute-force approach would require a double pass (hence $O(n^2)$), whereas a Sliding Window one can reduce it to a single one (hence $O(n)$).

Let's now look at both the static and dynamic cases.