Worst case scenario in case of linear search algorithm is __________. 

The correct answer is Item is not in the array at all.

Key Points

• In a linear search algorithm, the worst-case scenario occurs when the item being searched for is not present in the array at all.
• This is because the algorithm will have to check each element of the array one by one until it reaches the end of the array, only to determine that the item is not there.
• The time complexity for the worst-case scenario in linear search is O(n), where n is the number of elements in the array.
• Other scenarios like the item being at the last position or somewhere in the middle will not be as time-consuming as the item being absent.

Additional Information

• Linear search is a simple search algorithm that is easy to implement but not very efficient for large datasets.
• It does not require the array to be sorted, which is an advantage over other more complex search algorithms.
• In the average case, the time complexity of a linear search is O(n/2), but this simplifies to O(n) as constants are ignored in Big O notation.
• Linear search can be used on both arrays and linked lists.

/ Example of a linear search algorithm in Python
def linear_search(arr, target):
    for i in range(len(arr)):
        if arr[i] == target:
            return i
    return -1

# Example usage:
arr = [4, 2, 7, 1, 9, 3]
target = 7
result = linear_search(arr, target)
if result != -1:
    print(f"Element found at index {result}")
else:
    print("Element not found in the array")