public static void Main()
Console.Write("Nhap vao so phan tu: ");
int spt = Convert.ToInt32(Console.ReadLine());
int[] arr = new int[spt];
Console.WriteLine("Nhap gia tri vao tung phan tu: ");
for(int i=0; i<arr.Length; i++)
Console.Write("PHan tu thu {0}: ", i+1);
arr[i] = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Mang vua nhap");
Console.Write("{0} ", a);
Console.WriteLine("\nMang da sap xep");
Console.Write("{0} ", a);
static public void BubbleSort(ref int[] arr)
for(int i=0; i<arr.Length; i++)
for(int j=i+1; j<arr.Length; j++)