complexity of code

Question

what is the complexity of a program having only one loop, is it log n? can someone give me some ideas about estimating complexity of codes?

Answer 1

Well, that really depends on what is going on in that loop.

This loop is linear time, i.e., O(n):

int sum = 0;
foreach( int i in SomeCollection )
{
    sum += i;
}

However, consider a loop which performs a substring search during each iteration. Now you have to consider the complexity of the string searching algorithm. Your question can't be answered as it stands. You will need to provide a code sample if you want a meaningful answer.