Sliding Window Technique in Algorithm
The Sliding Window is an important technique used to efficiently solve problems related to arrays or strings. In this approach, we define a "window" (a subset of elements) that moves or slides over the data structure, without repeatedly iterating over the entire data.
The main goal of this technique is to reduce time complexity, especially when performing operations on subarrays or substrings.
Key Idea
- A fixed or variable size window is created
- The window is moved (slid) forward step by step
- Unnecessary calculations are avoided at each step
Types of Sliding Window
1. Fixed Size Window
The size of the window is fixed beforehand. Example: maximum sum subarray of size k.
2. Variable Size Window
The size of the window changes based on a condition. Example: longest substring without repeating characters.
Advantages
- Reduces time complexity (can be O(n))
- Makes code more optimized and efficient
- Performs better than brute force approaches
Example Use Cases
- Maximum sum subarray of size k
- Longest substring without repeating characters
- Minimum window substring





