一、冒泡排序

public static void 冒泡(int[] nums){//倒序
    boolean b = true;
    for (int i = 0,n = nums.length; i < n && b; i++) {
        b = false;
        for (int j = 0; j < n - i - 1; j++) {
            if (nums[j] < nums[j+1]){
                int temp = nums[j];
                nums[j] = nums[j+1];
                nums[j+1] = temp;
                b = true;
            }
        }
    }
    System.out.println(Arrays.toString(nums));
}

二、选择排序

public static void 选择(int[] nums){//倒序
    for (int i = 0,n = nums.length; i < n - 1; i++) {
        int maxIndex = i;
        for (int j = i; j < n; j++) {
            if (nums[j] > nums[maxIndex]){
                maxIndex = j;
            }
        }
        int temp = nums[i];
        nums[i] = nums[maxIndex];
        nums[maxIndex] = temp;
    }
    System.out.println(Arrays.toString(nums));
}

三、插入排序

public static void 插入(int[] nums){
    for (int i = 1,前一个元素值下标,n = nums.length; i < n; i++) {
        int 当前元素值 = nums[i];
        for (前一个元素值下标 = i - 1; 前一个元素值下标 >= 0 && nums[前一个元素值下标] > 当前元素值; 前一个元素值下标--) {
            nums[前一个元素值下标+1] = nums[前一个元素值下标];
        }
        // 作用：当走到这里已经证明前面的已经排好序，其中有一个位置是需要替换值的
        nums[前一个元素值下标 + 1] = 当前元素值;
    }
    System.out.println(Arrays.toString(nums));
}

四、快速排序

private static void quickSort(int[] nums) {
    quickSort(nums, 0, nums.length - 1);
}

/**
 * 先确定一个基准点，然后进行分区，递归排序子数组
 * @param nums
 * @param low 低
 * @param high 高
 */
private static void quickSort(int[] nums, int low, int high) {
    if (low >= high) { return; }
    int[] p = partition(nums, low, high);
    System.out.println("===============>" + Arrays.toString(p));
    quickSort(nums, low, p[0] - 1);
    quickSort(nums, p[0] + 1, high);
}

private static int[] partition(int[] nums, int low, int high) {
    int less = low - 1, more = high;
    System.out.println("less：" + less + ",more：" + more);
    System.out.println(Arrays.toString(nums));
    System.out.println(">>>>>>>>>>>>>>>>");
    while (low < more) {
        if (nums[low] < nums[high]) {
            swap(nums, ++less, low++);
            System.out.println(Arrays.toString(nums));
        } else if (nums[low] > nums[high]) {
            swap(nums, --more, low);
            System.out.println(Arrays.toString(nums));
        } else {
            ++low;
        }
    }
    System.out.println("<<<<<<<<<<<<<<<<");
    System.out.println(Arrays.toString(nums));
    System.out.println("more：" + more + ",high：" + high);
    swap(nums,more,high);
    System.out.println(Arrays.toString(nums));
    System.out.println("return：" + (less + 1) + "，" + more);
    return new int[] {less + 1, more};
}