public static int NhapN(string note) {
int n = int.Parse(Console.ReadLine());
public static int[,] NhapMaTran(string note) {
int n = NhapN("Nhap dong n: ");
int m = NhapN("Nhap cot m: ");
for (int i = 0; i < arr.GetLength(0); i++) {
for (int j = 0; j < arr.GetLength(1); j++) {
arr[i, j] = int.Parse(Console.ReadLine());
public static void XuatMaTran(int[,] arr, int m) {
for (int i = 0; i < arr.GetLength(0); i++) {
for (int j = 0; j < m; j++) {
Console.Write(arr[i, j] + " ");
public static void HoanVi(ref int a, ref int b) {
public static void HoanViCot(int[,] arr, int cot) {
for (int i = 0; i < arr.GetLength(0); i++) {
HoanVi(ref arr[i, cot], ref arr[i, cot - 1]);
public static void XoaDong(int[,] arr, int viTriCotXoa) {
int m = arr.GetLength(1);
for (int j = viTriCotXoa + 1; j < m; j++) {
public static void Main() {
arr = NhapMaTran("Nhap ma tran: ");