Contents
What is a Variable Length Array (Dynamic Array)?
A variable length array, also known as a dynamic array, is a data structure that allows its size to change dynamically during runtime. Unlike static arrays, which have a fixed size determined at compile time, dynamic arrays can resize themselves to accommodate new elements as needed.
Dynamic arrays are particularly useful when the number of elements in a collection is unknown or may vary. They provide the flexibility to allocate memory on-demand, which can help optimize memory usage and improve efficiency.
Techniques for Resizing Dynamic Arrays
Resizing a dynamic array involves allocating a new, larger block of memory, copying the existing elements to the new block, and deallocating the old block. This process ensures that the array can accommodate additional elements while preserving the integrity of the existing data.
Here are a few commonly used techniques for resizing dynamic arrays:
1. Incremental resizing: In this approach, the array’s size is increased by a fixed increment whenever it reaches its capacity. For example, if the array’s capacity is 10 and it is full, the size can be increased by 5, making the new capacity 15. While this technique is simple to implement, it may result in memory wastage if the increment is too large.
2. Geometric resizing: This technique involves increasing the size of the array by a multiple (e.g., doubling) whenever it reaches its capacity. For example, if the array’s capacity is 8 and it is full, the size can be doubled to 16. Geometric resizing allows for efficient use of memory and reduces the number of resizing operations required, but it may result in occasional over-allocation.
3. Adaptive resizing: Adaptive resizing is a combination of incremental and geometric resizing. It adjusts the increment or multiple based on the previous resizing history and the current size of the array. This approach aims to strike a balance between memory usage and efficiency by dynamically adapting the resizing strategy.
When resizing dynamic arrays, it is essential to consider the time complexity of the resizing operation. Depending on the implementation and resizing technique, the time complexity can range from O(n) (linear) to O(1) (constant) amortized.
Conclusion
Variable length arrays, or dynamic arrays, offer a flexible approach to handle collections whose size is unknown or constantly changing. By employing resizing techniques such as incremental, geometric, or adaptive resizing, dynamic arrays can efficiently allocate memory to accommodate additional elements while minimizing memory usage and maintaining performance.
Understanding the principles of resizing data structures can be invaluable for developers, enabling them to optimize their code and efficiently manage varying amounts of data. With dynamic arrays at their disposal, developers can handle unpredictable situations and build more robust and scalable applications.
Reference Articles
Read also
[Google Chrome] The definitive solution for right-click translations that no longer come up.