Searching

Understanding Searching in ArrayLists

  • Understand that searching is a fundamental operation performed on ArrayLists.
  • Know that searching in an ArrayList involves finding a specific element within it.
  • Appreciate that performing searches effectively is essential for the efficiency of software systems.

Linear Search

  • Learn that a linear search is the simplest search algorithm that works on ArrayLists, best used when the list is unsorted.
  • Understand that a linear search works by starting at the beginning of the ArrayList and checking each element until the desired one is found or all elements have been checked.
  • Recognise that while the linear search is simple and useful, it is not the most efficient for large ArrayLists.

Binary Search

  • Understand that a binary search is a more efficient searching algorithm, but it requires the ArrayList to be sorted.
  • Be aware that a binary search works by repeatedly dividing the search range in half until the desired element is found or the search range is empty.
  • Note that a binary search is significantly faster than a linear search for large sorted ArrayLists.

Implementing Search Algorithms

  • Recognise that code implementation of search algorithms uses loops and conditional statements.
  • Remember that when implementing a search algorithm, it’s important to handle cases where an element is not in the ArrayList. This is typically done by returning a value to indicate the absence of the searched element.

Search Efficiency

  • Understand the concept of computational complexity in the context of search operations.
  • Note that the efficiency of a search algorithm is measured in terms of the number of comparisons it must perform. This is often expressed as Big O notation, e.g., O(N) for a linear search and O(log N) for a binary search.
  • Appreciate that a more efficient search algorithm reduces the time required and can make a significant difference in large ArrayLists.

Practical Applications of Searching

  • Note that search operations are used in many everyday applications, from searching contacts on a phone to looking up products in an online store.
  • Appreciate the role of search algorithms in making these applications efficient and responsive.
  • Understand that choosing the appropriate search algorithm depends on the specific requirements of the software.