Is n or nlog(n) better than constant or logarithmic time?

Question

In the Princeton tutorial on Coursera the lecturer explains the common order-of-growth functions that are encountered. He says that linear and linearithmic running times are \"w

Answer 1

constant time is always better because the time (or space) complexity doesn't depend on the problem size... isn't it a great feature? :-)

then we have O(N) and then Nlog(N)

did you know? problems with constant time complexity exist!

e.g.

let A[N] be an array of N integer values, with N > 3. Find and algorithm to tell if the sum of the first three elements is positive or negative.