title: Why is the complexity of heap Delete element equal to O(logn) and Build is O(n)?
body: <p>I am having trouble with understanding complexity in general, can you please explain why is Delete complexity in heap equal to O(log n) and why is Build O(n)? ( I assume insertion  with complexity O(1) refers only to the adding of the element, without the place switching).
  Isn't the element that we add at the bottom suppose to move all the way up in the worst case? Therefore ( even though i don't understand why it is log n ) , shouldn't the Build be O(log n) as well?</p>