2 SwapSort

int BubbleSort(int *a, int len)
{
    int i;
    for(i = len-1; i > 0; i--)
    {　　int j;
        int flag = 0;
        for(j = 0; j < i; j++)
        {if(a[j] > a[j+1])
            {
                flag = 1;
                int temp = a[j];
                a[j] = a[j+1];
                a[j+1] = temp;
            }
        }
        if(flag == 0)
            break;
    }
}