Linear Search Algorithm

The Linear Search Algorithm, also known as the Sequential Search Algorithm, is a fundamental searching technique used for finding a specific element within a list or an array of elements. The algorithm works by iterating through each element in the list or array, comparing it with the target value. If the element being examined matches the target value, the algorithm stops and returns the index of the matching element. If the algorithm reaches the end of the list or array without finding the target element, it returns an indication that the value was not found, such as -1 or null. The primary advantage of the Linear Search Algorithm is its simplicity, as it requires no prior knowledge of the data structure or any specific ordering of the elements within the list or array. This makes it particularly useful for small datasets, unsorted lists, or when searching for multiple occurrences of a target value. However, the algorithm's performance can be quite slow for large datasets, as it has a worst-case time complexity of O(n), where n is the number of elements in the list or array. In such cases, more efficient search algorithms like Binary Search or Hash-based searching techniques can be employed for better performance.
/**
 * This file is part of Scalacaster project, https://github.com/vkostyukov/scalacaster
 * and written by Vladimir Kostyukov, http://vkostyukov.ru
 *
 * Linear Search https://en.wikipedia.org/wiki/Linear_search
 *
 * Worst - O(n)
 * Best - O(1)
 * Average - O(n)
 */

def linearsearch[A](list: List[A], key: A): Option[A] = {
  def search(as: List[A]): Option[A] = 
    if (as.isEmpty) None
    else if (as.head == key) Some(as.head)
    else search(as.tail)

  search(list)
}

LANGUAGE:

DARK MODE: