Linear Search

What is Linear Search?

Linear search known as sequential search. It is a simple searching algorithm that checks every element in a list or array one by one until it finds the target value or reaches the end of the list.

Of course, Linear Search is not the most efficient for large datasets, but it does not require the data to be sorted and is easy to implement.

How it works?

Assuming we have an array [4, 2, 7, 1, 3] and we are searching for the target value 1:

• We start at the first element (4) and compare it to the target (1). Since they are not equal, we move to the next element.
• We compare the second element (2) to the target (1). Again, they are not equal, so we move on.
• We compare the third element (7) to the target (1). Still not equal, so we continue.
• We compare the fourth element (1) to the target (1). This time, they are equal, so we have found the target at index 3.

Implementation

def linear_search(arr: list, target: int) -> int:
    for index, value in enumerate(arr):
        if value == target:
            return index
    return -1
 
data = [4, 2, 7, 1, 3]
search_target = 1
 
result = linear_search(data, search_target)
if result != -1:
    print(f"Element {search_target} found at index {result}.")
else:
    print(f"Element {search_target} not found in the array.")

Visualization