Data Structures and Algorithms: Lecture 2 - Arrays

An array is a similar type of collection of items stored at contiguous memory locations. It allows for storing multiple items of the same type together.

False

Arrays simplify storing and accessing multiple items of the same type efficiently by organizing them in contiguous memory locations. This allows for calculations of element positions easily by adding an offset to the array's base value, facilitating direct access to any element without the need to traverse the entire data structure.

<p>Single Dimensional Array: stores data as a single list. Two Dimensional Array: stores data in a tabular format.</p> Signup and view all the answers

<p>To declare a single dimensional array, you need to specify the data type of the elements, the name of the array, followed by square brackets containing the size of the array. For example: <code>int student[10];</code> This statement declares an array named <code>student</code> that can hold 10 integer elements.</p> Signup and view all the answers

<p>To access the last element of a single dimensional array, you subtract 1 from the array's size and use it as an index within the square brackets. For instance, <code>num[9]</code> refers to the last element in an array named <code>num</code> that is 10 elements long, with indices ranging from 0 to 9.</p> Signup and view all the answers

<p>The syntax for declaring a two dimensional array involves specifying the data type, the name of the array, followed by square brackets containing the number of rows, and another set of square brackets containing the number of columns. For example: <code>int sales[3][12];</code> This declares a two dimensional array named <code>sales</code> with 3 rows and 12 columns.</p> Signup and view all the answers

<p>Arrays offer advantages such as random access to elements using their indices, efficient code writing by creating a single array for multiple elements, easy access to all elements, efficient traversal using a single loop, and simplified sorting operations due to reduced code lines.</p> Signup and view all the answers

<p>Dynamic resizing to accommodate changing data</p> Signup and view all the answers

<p>The <code>java.util.Arrays</code> class provides a set of functionalities for effectively managing and processing arrays in Java. It simplifies various tasks such as sorting, searching, and manipulating arrays.</p> Signup and view all the answers

<p>Linear search is a basic searching algorithm that sequentially traverses an array or list to locate a specific element. It examines elements one at a time until a match is found or the entire list is exhausted.</p> Signup and view all the answers

<p>Linear search is the simplest due its direct and sequential nature. Unlike more sophisticated algorithms involving sorting or divide-and-conquer techniques, it involves comparing the search element with each element of the array in a fixed order until a match is found or the list is exhausted.</p> Signup and view all the answers

<p>Linear search is most effective when no prior information about the array structure or order is available. Additionally, it is a preferred choice for smaller datasets where the time taken for its sequential traversal is not significantly detrimental to the overall efficiency.</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>The core of binary search lies in repeatedly dividing the search space into halves. It begins by comparing the search element with the middle element of the sorted array. If they match, the search is complete. If the search element is smaller, it narrows down the search to the left half of the array. Otherwise, it proceeds with the right half. This process of repeatedly dividing the search space into halves ensures that the algorithm quickly homes in on the desired element.</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>The crucial requirement for binary search is that the array must be sorted. This sorting allows the algorithm to effectively eliminate half of the search space with each comparison, making it considerably faster than linear search for large datasets.</p> Signup and view all the answers

<p>To apply binary search to an unsorted array, you must first sort the array using a suitable sorting algorithm. Once the array is sorted, you can proceed with the binary search algorithm to efficiently locate the target element.</p> Signup and view all the answers

<p>Requires an unsorted array to function effectively</p> Signup and view all the answers