All Flashcards
What is the core idea behind Selection Sort?
Repeatedly selecting the smallest element and moving it to the sorted portion.
What is the core idea behind Insertion Sort?
Building a sorted subarray by inserting elements from the unsorted portion into their correct positions.
How do you determine if an ArrayList is sorted?
Iterate through the list, checking if each element is less than or equal to the next.
What is the purpose of sorting algorithms?
To arrange elements in a specific order, typically ascending or descending, for easier searching and data retrieval.
What is the significance of run-time comparisons?
They help in understanding the efficiency of different algorithms and choosing the best one for a specific task.
What are the two subarrays in Selection Sort?
Sorted subarray and unsorted subarray.
What are the two subarrays in Insertion Sort?
Sorted subarray and unsorted subarray.
Why is it important to check if an ArrayList is sorted?
To ensure data integrity and efficiency in search and retrieval operations.
What is the main goal of comparing sorting algorithms?
To understand their relative efficiency and choose the best one for a given situation.
What is the role of swapping in sorting algorithms?
To rearrange elements in the correct order.
What are the differences between Selection Sort and Insertion Sort?
Selection Sort: Finds the minimum element and swaps. | Insertion Sort: Inserts elements into the sorted portion.
Selection Sort vs. Insertion Sort: Data Accesses
Selection Sort: Requires more data accesses and modifications. | Insertion Sort: Requires fewer data accesses and modifications.
Selection Sort vs. Insertion Sort: Best case scenario
Selection Sort: Performance not affected by input. | Insertion Sort: More efficient when data is partially sorted.
Selection Sort vs. Insertion Sort: Implementation Complexity
Selection Sort: Generally simpler to implement. | Insertion Sort: Slightly more complex due to shifting elements.
Selection Sort vs. Insertion Sort: Performance on small datasets
Selection Sort: Performance is generally consistent. | Insertion Sort: Can be faster for small, nearly sorted datasets.
Selection Sort vs. Insertion Sort: Number of swaps
Selection Sort: Performs fewer swaps. | Insertion Sort: Performs more swaps.
Selection Sort vs. Insertion Sort: Adaptability
Selection Sort: Not adaptive (doesn't take advantage of existing order). | Insertion Sort: Adaptive (performs better on nearly sorted data).
Selection Sort vs. Insertion Sort: Use cases
Selection Sort: Suitable for small datasets where minimizing writes is important. | Insertion Sort: Suitable for small datasets or when data is nearly sorted.
Selection Sort vs. Insertion Sort: Worst-case time complexity
Selection Sort: O(n^2). | Insertion Sort: O(n^2).
Selection Sort vs. Insertion Sort: Space complexity
Selection Sort: O(1). | Insertion Sort: O(1).
What does this code do?
java
public static boolean isSorted(ArrayList<Integer> array) {
for (int i = 0; i < array.size() - 1; i++) {
if (array.get(i + 1) < array.get(i)) {
return false;
}
}
return true;
}
Checks if an ArrayList of Integers is sorted in ascending order.
What is the purpose of the outer loop in the selectionSort method?
To traverse to the second to last item in the ArrayList.
What is the purpose of the inner loop in the selectionSort method?
To find the smallest remaining item in the unsorted portion of the ArrayList.
What is the purpose of the outer loop in the insertionSort method?
To iterate through the ArrayList, considering each element for insertion into the sorted portion.
What is the purpose of the inner loop in the insertionSort method?
To shift elements to the right to create space for inserting the current element in its correct position.
What is the error in the following code?
java
public static ArrayList<Integer> selectionSort(ArrayList<Integer> array) {
for (int i = 0; i < array.size(); i++) { // Error is here
int smallestIndex = i;
int smallestElement = array.get(i);
for (int j = i + 1; j < array.size(); j++) {
if (array.get(j) < smallestElement) {
smallestIndex = j;
smallestElement = array.get(j);
}
}
if (smallestIndex > i) {
int originalItem = array.get(i);
array.set(i, smallestElement);
array.set(smallestIndex, originalItem);
}
}
return array;
}
The outer loop should iterate up to array.size() - 1 to avoid an IndexOutOfBoundsException.
What is the error in the following code?
java
public static ArrayList<Integer> insertionSort(ArrayList<Integer> array) {
for (int i = 1; i < array.size(); i++) {
int currentElement = array.get(i);
int currentIndex = i;
for (int j = i; j > 0; j++) {
if (currentElement < array.get(j - 1)) { // shifting the item left until properly placed by swapping consecutive items
int itemToRight = array.get(j - 1);
array.set(j - 1, currentElement);
array.set(j, itemToRight);
}
}
}
return array;
}
There is no error in the code.
Predict the output:
java
ArrayList<Integer> list = new ArrayList<>(Arrays.asList(5, 2, 8, 1, 9));
selectionSort(list);
System.out.println(list);
[1, 2, 5, 8, 9]
Predict the output:
java
ArrayList<Integer> list = new ArrayList<>(Arrays.asList(5, 2, 8, 1, 9));
insertionSort(list);
System.out.println(list);
[1, 2, 5, 8, 9]
Complete the code:
java
public static boolean isSorted(ArrayList<Integer> array) {
for (int i = 0; i < array.size() - 1; i++) {
if (array.get(i + 1) < array.get(i)) {
// Complete this line
}
}
return true;
}
return false;