Question

I calculate the optimal case complexity, average, and worst of this algorithm in java, I think if good is O (1) in the worst case is O (n), but I do not know if average! could you help me on how to calculate it? thank you!

public boolean searchFalse(boolean[] b){ 
 boolean trovato=false; 
  for(int i=0;i<b.length;i++){
   if(b[i]==false){
 trovato=true;
 break;
   }
  }return trovato;
}

Answer 1

I couldn’t resist re-writing it

public boolean searchFalse(boolean[] bs){
    for (boolean b : bs) if(!b) return true;
    return false;
}

This stops after the first element potentially O(1).

If all the boolean are random the average search time is O(1) as you perform 2 searches on average, or if there is typically one false value in a random position the average is O(N)

If it has to search all the way, the worst case is O(N)

In short O(N/2) = O(N)