A: basic introduction bubbling
II: practical application
static void Main(string[] args)
{
int[] arr = {3,9,-1,10,20 };
for (int i = 0; i < arr.Length - 1; i++)
{
for (int j = 0; j < arr.Length - 1 - i; j++)
{
if (arr[i] < arr[j])
{
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}
Console.Write("第" + (i + 1) + "趟排序后的数组：");
print(arr);
}
Console.WriteLine("最后的结果:");
print(arr);
}
public static void print(int[] arr)
{
for (int i = 0; i < arr.Length; i++)
{
Console.Write(arr[i] + "\t");
}
Console.WriteLine("");
}
Three: Optimization of Bubble Sort
Introducing a switch, if the exchange is not traversed value, indicating the correct order is not necessary to traverse back again many times.
static void Main(string[] args)
{
int[] arr = {3,9,-1,10,20 };
bool flag = false;//标识变量，表示是否进行交换
for (int i = 0; i < arr.Length - 1; i++)
{
for (int j = 0; j < arr.Length - 1 - i; j++)
{
if (arr[j] > arr[j+1])
{
flag = true;
int temp = arr[j];
arr[j] = arr[j+1];
arr[j+1] = temp;
}
}
Console.Write("第" + (i + 1) + "趟排序后的数组：");
print(arr);
if (flag)//在一趟排序中，依次交换都没有发生过
{
flag = false;//重置flag，进行下次判断
}
else
{
break;
}
}
Console.WriteLine("最后的结果:");
print(arr);
}
public static void print(int[] arr)
{
for (int i = 0; i < arr.Length; i++)
{
Console.Write(arr[i] + "\t");
}
Console.WriteLine("");
}
想比较上面的写法，减少了一次遍历。
四：比较排序的效率
int len = 10;//修改数据量
int[] arrs = new int[len];
for (int i = 0; i < len; i++)
{
Random random = new Random();
int a = (int)random.Next(0, len);
arrs[i] = a;
Thread.Sleep(1);
}
Console.WriteLine("排序前的时间是"+DateTime.Now.ToString("HH:mm:ss fff"));
bubbleSort(arrs);
Console.WriteLine("排序后的时间是" + DateTime.Now.ToString("HH:mm:ss fff"));
public static void bubbleSort(int[] arr)
{
bool flag = false;//标识变量，表示是否进行交换
for (int i = 0; i < arr.Length - 1; i++)
{
for (int j = 0; j < arr.Length - 1 - i; j++)
{
if (arr[j] > arr[j + 1])
{
flag = true;
int temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
// Console.Write("第" + (i + 1) + "趟排序后的数组：");
// print(arr);
if (flag)//在一趟排序中，依次交换都没有发生过
{
flag = false;//重置flag，进行下次判断
}
else
{
break;
}
}
}
10个数据冒泡排序比较1000个数据：
当数据量越大，所需要的时间越长！