cppreference.com -> Complexity

Complexity

There are different measurements of the speed of any given algorithm. Given an input size of N, they can be described as follows:

Name Speed Description
exponential time slow takes an amount of time proportional to a constant raised to the Nth power (K^N)
polynomial time fast takes an amount of time proportional to N raised to some constant power (N^K)
linear time faster takes an amount of time directly proportional to N (K * N)
logarithmic time much faster takes an amount of time proportional to the logarithm of N (log(N))
constant time fastest takes a fixed amount of time, no matter how large the input is (K)