Space complexity refers to the amount of memory or storage space required by an algorithm to solve a problem. It is a measure of how much memory an algorithm uses as a function of the size of the input.
Some common methods of measuring space complexity include counting the amount of memory used by the algorithm, counting the number of temporary variables and data structures used by the algorithm, or analyzing the memory footprint of the program as it runs.
How do We declare it?
To declare the space complexity of an algorithm, it is usually best to measure it using a combination of these methods and to express it in terms of the size of the input.
There are several factors that can impact the space complexity of an algorithm, including:
Data structures used: The type and size of data structures used by an algorithm can greatly impact its space complexity. For example, using a linked list instead of an array to store data can increase the space complexity, as linked lists typically require additional memory to store the pointers between elements.
Recursion: Recursive algorithms often require additional memory to store the intermediate results of each recursive call, which can increase the space complexity of the algorithm.
Size of input: The size of the input can greatly impact the space complexity of an algorithm. Algorithms that require storing a large amount of data or intermediate results will have a higher space complexity.
Computational complexity: The computational complexity of an algorithm, which is a measure of the time required to solve a problem, can also impact its space complexity. Algorithms that require a large amount of processing time often require more memory to store intermediate results, which can increase their space complexity.
Note: It is essential to consider the space complexity of an algorithm when choosing an algorithm to solve a problem. High space complexity can lead to decreased performance, longer processing times, and increased memory usage, making an algorithm less suitable for practice.