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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;
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 general steps of Selection Sort?
1. Find the smallest element in the unsorted portion. 2. Swap it with the first element of the unsorted portion. 3. Repeat for the remaining unsorted portion.
What are the general steps of Insertion Sort?
1. Assume the first element is sorted. 2. Take the next element and insert it into the correct position in the sorted portion. 3. Repeat for all remaining elements.
What are the steps to check if an ArrayList is sorted?
1. Iterate through the list. 2. Compare each element with the next. 3. If any element is greater than the next, the list is not sorted.
Steps of Selection Sort (detailed)
1. Find the minimum element in the unsorted array. 2. Swap the found minimum element with the first element of the unsorted array. 3. Move to the next element in the unsorted array. 4. Repeat until the array is sorted.
Steps of Insertion Sort (detailed)
1. Iterate from the second element to the end of the array. 2. For each element, compare it with the elements before it. 3. Shift the elements greater than the current element to one position ahead of their current position. 4. Insert the current element in the correct position.
Steps to determine if an ArrayList is sorted (detailed)
1. Start from the first element of the ArrayList. 2. Compare each element with the next element in the ArrayList. 3. If any element is greater than the next element, return false. 4. If the end of the ArrayList is reached, return true.
What is the first step in Selection Sort?
Find the smallest element in the unsorted portion.
What is the first step in Insertion Sort?
Assume the first element is sorted.
What is the first step to check if an ArrayList is sorted?
Iterate through the list.
What is the last step in Selection Sort?
Repeat for the remaining unsorted portion.