冒泡排序

冒泡排序1：

public class Bubbling {

    public static void sort(int array[]) {
        for(int i =0; i < array.length -1; i++) {

            for(int j = 0; j < array.length -1 -i; j++) {
                int tmp = 0;
                if(array[j] > array[j+1]) {
                    tmp = array[j];
                    array[j] = array[j+1];
                    array[j+1] = tmp;
                }
            }
        }
    }

    public static void main(String[] args){
        int[] array = new int[]{5,8,6,3,9,2,1,7};
        sort(array);
        System.out.println(Arrays.toString(array));
    }
}

---

冒泡排序优化2

public class Bubbling1 {

    public static void sort(int array[]) {
        for(int i =0; i < array.length -1; i++) {
            //有序标记，每一轮的初始值都是true
            boolean isSorted = true;
            for(int j = 0; j < array.length -1 -i; j++) {
                int tmp = 0;
                if(array[j] > array[j+1]) {
                    tmp = array[j];
                    array[j] = array[j+1];
                    array[j+1] = tmp;
                    //因为有元素进行交换，所以不是有序的，标记变为false
                    isSorted = false;
                }

            }
            if(isSorted){
                break;
            }
        }
    }

    public static void main(String[] args){
        int[] array = new int[]{5,8,6,3,9,2,1,7};
        sort(array);
        System.out.println(Arrays.toString(array));
    }
}

---

冒泡排序优化3

public class Bubbling2 {

    public static void sort(int array[]) {
        //记录最后一次交换的位置
        int lastExchangeIndex = 0;
        //无序数列的边界，每次比较只需要比到这里为止
        int sortBorder = array.length - 1;
        for(int i =0; i < array.length -1; i++) {
            //有序标记，每一轮的初始值都是true
            boolean isSorted = true;
            for(int j = 0; j < sortBorder; j++) {
                int tmp = 0;
                if(array[j] > array[j+1]) {
                    tmp = array[j];
                    array[j] = array[j+1];
                    array[j+1] = tmp;
                    //因为有元素进行交换，所以不是有序的，标记变为false
                    isSorted = false;
                    // 更新为最后一次交换元素的位置
                    lastExchangeIndex = j;
                }

            }
            sortBorder = lastExchangeIndex;
            if(isSorted){
                break;
            }
        }
    }

    public static void main(String[] args){
        int[] array = new int[]{5,8,6,3,9,2,1,7};
        sort(array);
        System.out.println(Arrays.toString(array));
    }
}

---

冒泡排序4

public class Bubbling3 {
    public static void sort(int array[]) {
        int tmp = 0;
        for(int i=0; i<array.length/2; i++) {
            //有序标记，每一轮的初始值都是true
            boolean isSorted = true;
            //奇数轮，从左向右比较和交换
            for(int j=i; j<array.length-i-1; j++) {
                if(array[j] > array[j+1]) {
                    tmp = array[j];
                    array[j] = array[j+1];
                    array[j+1] = tmp;
                    //因为有元素进行交换，所以不是有序的，标记变为false
                    isSorted = false;
                }

            }

            if(isSorted){
                break;
            }
            // 在偶数轮之前，将isSorted重新标记为true
            isSorted = true;
            //偶数轮，从右向左比较和交换
            for(int j=array.length-i-1; j>i; j--) {
                if(array[j] < array[j-1]) {
                    tmp = array[j];
                    array[j] = array[j-1];
                    array[j-1] = tmp;
                    //因为有元素进行交换，所以不是有序的，标记变为false
                    isSorted = false;
                }
            }

            if(isSorted){
                break;
            }
        }
    }

    public static void main(String[] args){
        int[] array = new int[]{2,3,4,5,6,7,8,1};
        sort(array);
        System.out.println(Arrays.toString(array));
    }
}