How to determine the efficiency of searching for an element in an array in terms of algorithmic complexity?

The efficiency of searching for an element in an array is usually evaluated based on algorithmic complexity in terms of time — how many operations are required in the worst, average, and best cases.

For a simple unsorted array, searching is typically implemented as a linear scan — checking each element in order. Its time complexity is O(n), where n is the number of elements.

If the array is sorted, binary search can be used, which operates in O(log n).

To determine efficiency, you need to:

• Understand whether the array is sorted.
• Choose the search algorithm (linear or binary).
• Estimate the number of operations depending on the array size.

Example of linear search in Swift:

func linearSearch(array: [Int], target: Int) -> Int? {
    for (index, element) in array.enumerated() {
        if element == target {
            return index
        }
    }
    return nil
}

In this example, the complexity is O(n).