Linear Search Algorithm - Explanation and Implementation

What is Linear Search?

Definition: Linear Search is a simple searching algorithm that traverses through each element of an array sequentially to find the target element.

Use Case: It's effective for small data sets or unsorted arrays where other algorithms like binary search are not feasible.

Algorithm Steps:

• Start at the first element of the array.
• Compare the current element with the target.
• If a match is found, return the index.
• If the loop completes without a match, return -1 (element not found).

Python Code:

def linear_search(arr, target):
    for i in range(len(arr)):
        if arr[i] == target:
            return i  # Element found, return index
    return -1  # Element not found

# Example Usage
arr = [10, 20, 30, 40, 50]
target = 30
result = linear_search(arr, target)

if result != -1:
    print(f"Element found at index {result}")
else:
    print("Element not found")

Test Case:

Input:
arr = [10, 20, 30, 40, 50]
target = 30

Output:
Element found at index 2

Time Complexity:

• Best Case: O(1), when the target is the first element.
• Worst Case: O(n), when the target is the last element or not found.
• Average Case: O(n).

Nandi Vardhan
Data Scientist, content creator, and passionate educator in the field of machine learning and data science.