Can you explain what is meant by algorithm complexity assessment?

Algorithm complexity estimation is a way to measure how the execution time or memory consumption of an algorithm changes depending on the size of the input data.

Main types of complexity:

• Time complexity — how many operations the algorithm performs.
• Space complexity — how much memory it uses.

It is most often expressed in "Big O" notation, for example, O(1), O(n), O(n²), where n is the size of the input data.

Example: if an algorithm iterates over all elements of an array once, its time complexity is O(n). If a nested loop iterates over an array inside another loop, the complexity is O(n²).

Estimating complexity helps understand how scalable and efficient an algorithm is with large data.