Bubble Sort vs Selection Sort: Which is Better?

What are the main differences between bubble sort and selection sort?

Bubble sort repeatedly steps through the list, swapping adjacent elements if they are in the wrong order. Selection sort, on the other hand, divides the list into a sorted and an unsorted region, repeatedly selecting the smallest (or largest) element from the unsorted region and moving it to the sorted region.

Which one is more efficient for large datasets?

Generally, selection sort is more efficient than bubble sort for larger datasets because it makes fewer swaps. However, both algorithms have a time complexity of O(n^2), making them inefficient for very large datasets compared to more advanced algorithms like quicksort or mergesort.

Can you provide a simple C++ implementation for both?

Sure! Here's a simple implementation:

// Bubble Sort
void bubbleSort(int arr[], int n) {
    for (int i = 0; i < n-1; i++) {
        for (int j = 0; j < n-i-1; j++) {
            if (arr[j] > arr[j+1]) {
                swap(arr[j], arr[j+1]);
            }
        }
    }
}

// Selection Sort
void selectionSort(int arr[], int n) {
    for (int i = 0; i < n-1; i++) {
        int minIndex = i;
        for (int j = i+1; j < n; j++) {
            if (arr[j] < arr[minIndex]) {
                minIndex = j;
            }
        }
        swap(arr[minIndex], arr[i]);
    }
}

Let me know if you need further explanations!

What are the best use cases for each sorting algorithm?

Bubble sort is mainly used for educational purposes due to its simplicity, while selection sort can be useful when memory write operations are costly, as it makes the minimum number of swaps. However, for practical applications, more efficient algorithms are recommended.