Which of the following is a valid array declaration in a common programming language (syntax may vary slightly)?
Explanation:
Different programming languages have slightly different syntax for array declarations. The options provided represent common variations, and all are valid in at least one popular language.
Accessing an element outside the valid index range of an array leads to what kind of error?
Explanation:
Programming languages have mechanisms to prevent accessing memory locations outside the bounds of an array, typically resulting in an IndexError or a similar exception.
Which operation is typically NOT efficient on a standard array?
Explanation:
Inserting at the beginning requires shifting all existing elements by one position to make space, making it less efficient, especially for large arrays.
What is the time complexity of finding the length of an array in most programming languages?
Explanation:
Programming languages typically store the length of an array as metadata, allowing for constant-time access to this information.
How can you efficiently delete a specific element from the middle of a sorted array while maintaining the sorted order?
Explanation:
To preserve the order in a sorted array, you need to move all elements after the deleted one to fill the gap.
What is the purpose of having a base address associated with an array in memory?
Explanation:
The base address acts as a reference point. Knowing the base address and the size of each element allows calculation of the location of any element in the array.
Given an array of integers, how can you efficiently count the occurrences of a specific element?
Explanation:
While other options work, iterating through the array and counting is the most straightforward and efficient approach for this specific task.
What is the primary advantage of using binary search over linear search?
Explanation:
Binary search has a time complexity of O(log n) while linear search has O(n), making binary search significantly faster for large datasets, but it requires the array to be sorted.
Which of the following sorting algorithms has the best average-case time complexity?
Explanation:
Merge Sort has a consistent O(n log n) time complexity in all cases, making it generally more efficient than the other options, especially for larger arrays.
What is the time complexity of finding the maximum element in a sorted array?
Explanation:
In a sorted array, the maximum element is always at the end (or beginning depending on sort order), so we can access it directly in constant time.
You want to find the first occurrence of a specific element in a sorted array. Which search algorithm is the most efficient?
Explanation:
Binary search can efficiently locate the first occurrence in a sorted array by repeatedly dividing the search interval in half.
What is the main disadvantage of using bubble sort for large datasets?
Explanation:
Bubble sort has a worst-case and average-case time complexity of O(n^2), making it highly inefficient for sorting large datasets.
You need to search for an element in an array where elements are randomly placed. Which search algorithm is your only option?
Explanation:
Binary search requires the array to be sorted. Since the array has randomly placed elements, linear search is the only viable option.
What is a key difference between a 1D array and a 2D array?
Explanation:
The primary distinction lies in their structure. 1D arrays are linear, holding elements in a single row. In contrast, 2D arrays are organized in rows and columns, forming a table-like structure.
How is an element at row 'i' and column 'j' typically accessed in a 2D array named 'matrix'?
Explanation:
In most programming languages, you use two indices within square brackets. The first index 'i' specifies the row, and the second index 'j' specifies the column.
What is the time complexity of accessing an element in a 2D array with 'm' rows and 'n' columns?
Explanation:
Accessing an element in a 2D array involves a constant-time operation. You directly compute the memory location using the row and column indices, making the access time independent of the array size.
Imagine a 2D array representing a grayscale image. Each element holds a pixel intensity value. How would you swap two rows 'r1' and 'r2' in this array?
Explanation:
To swap rows efficiently, you iterate through each column and exchange the elements at the corresponding positions in the rows 'r1' and 'r2'.
You are given a 2D array representing a matrix. What does transposing this matrix mean?
Explanation:
Transposing a matrix involves interchanging its rows and columns. The element at row 'i' and column 'j' becomes the element at row 'j' and column 'i'.
What is the space complexity of storing a 2D array with 'm' rows and 'n' columns?
Explanation:
The space complexity is determined by the total number of elements in the 2D array. Since you have 'm' rows and 'n' columns, you need to store a total of 'm * n' elements.
Consider a 2D array storing characters to represent a word search grid. You want to check if a given word exists in the grid horizontally or vertically. Which algorithm would be suitable for this task?
Explanation:
DFS is well-suited for exploring paths in a grid. Starting from a cell containing the first letter of the word, you can recursively explore adjacent cells (up, down, left, right) to see if they form the complete word.