Sorting Algorithms

 1. Bubble sort.

public static int bubble3(int[] arr) {
    boolean swapped;
    int count = 0;
    int n = arr.length;
    for (int i = 0; i < n - 1; i++) {
        swapped = false;
        for (int j = 0; j < n - i - 1; j++) {
            count++;
            if (arr[j] > arr[j + 1]) {
                swapped = true;
                int temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
            }
        }
        if (!swapped) break;
    }
    return count;
}

2. Selection sort.

public static int selectionSort1(int[] arr) {
    int count = 0;
    int n = arr.length;
    for (int i = 0; i < n - 1; i++) {
        int min = i;
        for (int j = i + 1; j < n; j++) {
            count++;
            if (arr[j] < arr[min]) {
                min = j;
            }
        }
        if (min != i) {
            int temp = arr[i];
            arr[i] = arr[min];
            arr[min] = temp;
        }
    }
    return count;
}

improved version:

public static int selectionSort2(int[] arr) {
    int count = 0;
    int n = arr.length;
    for (int i = 0; i < n - 1; i++) {
        int min = i;
        for (int j = i; j < n; j++) {
            count++;
            if (arr[j] < arr[min]) {
                min = j;
            }
        }
        if (min != i) {
            int temp = arr[i];
            arr[i] = arr[min];
            arr[min] = temp;
        } else {
            break;
        }
    }
    return count;
}

3. Insertion sort

public static void insertionSort(int[] arr) {
    int n = arr.length;
    for (int i = 1; i < n; i++) {
        int temp = arr[i];
        int j = i;
        while (j > 0 && arr[j - 1] > temp) {
            arr[j] = arr[j - 1];
            j--;
        }
        arr[j] = temp;
    }
}

public static void insertionSort(int[] arr) {
    int n = arr.length;
    for (int i = 0; i < n - 1; i++) {
        for (int j = i + 1; j > 0; j--) {
            if (arr[j] < arr[j - 1]) {
                int temp = arr[j];
                arr[j] = arr[j - 1];
                arr[j - 1] = temp;
            } else {
                break;
            }
        }
    }
}