Sliding Window

Sliding Window is a common problem-solving technique used mainly with arrays and strings. It helps optimize problems where we need to process a continuous range of elements, such as finding the maximum sum, longest substring, or minimum window. Instead of recalculating values for every possible subarray, the window moves step by step and reuses previous computations. This often reduces the time complexity from O(n²) to O(n). In this section, you’ll learn fixed-size and variable-size sliding window problems with simple explanations and examples.