写法1：
int[] arr = { 23, 44, 66, 76, 98, 11, 3, 9, 7 };
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])
{
int temp = arr[j + 1];
arr[j + 1] = arr[j];
arr[j] = temp;
}
}
}
写法2：
for (int i = 0; i < arr.Length; i++)
{
for (int j = i+1; j < arr.Length; j++)
{
if (arr[i] > arr[j])
{
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}
}
写法3：
for (int i = 0; i < arr.Length ; i++)
{
for (int j = 1; j < arr.Length - i; j++)
{
if (arr[j-1] > arr[j ])
{
int temp = arr[j + 1];
arr[j + 1] = arr[j];
arr[j] = temp;
}
}
}