Top "Complexity-theory" questions

Computational complexity theory is a branch of the theory of computation in theoretical computer science and mathematics that focuses on classifying computational problems according to their inherent difficulty.

upper bound, lower bound

What does it mean to prove an upper bound or lower bound to an algorithm?

algorithm complexity-theory time-complexity
Intuitive explanation for why QuickSort is n log n?

Is anybody able to give a 'plain english' intuitive, yet formal, explanation of what makes QuickSort n log n? From …

algorithm complexity-theory quicksort
What is the runtime complexity of python list functions?

I was writing a python function that looked something like this def foo(some_list): for i in range(0, len(…

python complexity-theory
What's the Time Complexity of Average Regex algorithms?

I'm not new to using regular expressions, and I understand the basic theory they're based on--finite state machines. I'm not …

regex algorithm complexity-theory
What is O(log* N)?

What is O(log* N) and how is it different from O(log N)?

algorithm math complexity-theory logarithm iterated-logarithm
What is the complexity of regular expression?

What is the complexity with respect to the string length that takes to perform a regular expression comparison on a …

regex complexity-theory big-o
Java CharAt() and deleteCharAt() performance

I've been wondering about the implementation of charAt function for String/StringBuilder/StringBuffer in java what is the complexity of …

java performance string complexity-theory stringbuilder
Different decision tree algorithms with comparison of complexity or performance

I am doing research on data mining and more precisely, decision trees. I would like to know if there are …

performance machine-learning complexity-theory classification decision-tree
Why is the knapsack problem pseudo-polynomial?

I know that Knapsack is NP-complete while it can be solved by DP. They say that the DP solution is …

language-agnostic complexity-theory dynamic-programming knapsack-problem
What is O(1) space complexity?

I am having a hard time understanding what is O(1) space complexity. I understand that it means that the space …

complexity-theory space-complexity