Question

def sorted(numbers):
num = numbers[0]
for i in numbers:
if i < num:
return False
num = i
return True

State a best-case and a worst-case scenario for your algorithm. Explain the Big-O complexity of each scenario. Use comparison as the basic unit of computation. Take into account the complexity of any list operation you use

Answer 1

Best case:
------------
if the first two numbers are not in sorted order
which means if i < num for first number in numbers list, then the function directly return False.
so, in this case only one statement was executed.
so, in best case time complexity is O(1)
Answer: O(1)

Worst case:
------------
If the list is sorted, then all of the i < num is not True.
so, it iterates n times if the numbers list is sorted.
so, in worst case time complexity is O(n)
Answer: O(n)