#include<stdio.h>
#include<conio.h>
#include<math.h>
#define MAX 100
void NhapMaTran(int a[][MAX], int &n)
{
	do
	{
		printf("\nNhap n: ");
		scanf("%d", &n);
		if(n < 1 || n > MAX)
		{
			printf("\nSo phan tu khong hop le. Xin kiem tra lai !");
		}
	}while(n < 1 || n > MAX);

	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			printf("\nNhap vao a[%d][%d] = ", i, j);
			scanf("%d", &a[i][j]);
		}
	}
}

void XuatMaTran(int a[][MAX], int n)
{
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < n; j++)
		{
			printf("%4d",a[i][j]);
		}
		printf("\n\n");
	}
}


void HoanVi(int &a, int &b)
{
	int temp = a;
	a = b;
	b = temp;
}

void HoanVi2Dong(int a[][MAX], int n, int dong1, int dong2)
{
	if((dong1 >= 0 && dong1 < n) && (dong2 >= 0 && dong2 < n))
	{
		for(int j = 0; j < n; j++)
		{
			HoanVi(a[dong1][j], a[dong2][j]);
		}
	}
}

int main()
{
	int a[MAX][MAX], n, dong1, dong2;
	NhapMaTran(a,n);
	XuatMaTran(a,n);
	do
	{
		printf("\nNhap dong 1: ");
		scanf("%d", &dong1);

		if(dong1 < 0 || dong1 >= n)
		{
			printf("\nDong khong hop le. Xin Nhap lai!");
		}
	}while(dong1 < 0 || dong1 >= n);

	do
	{
		printf("\nNhap dong 2: ");
		scanf("%d", &dong2);

		if(dong2 < 0 || dong2 >= n)
		{
			printf("\nDong khong hop le. Xin Nhap lai!");
		}
	}while(dong2 < 0 || dong2 >= n);

	HoanVi2Dong(a, n, dong1, dong2);

	printf("\nMa tran sau khi hoan vi dong %d va dong %d \n", dong1, dong2);
	XuatMaTran(a, n);

	getch();
	return 0;
}

Line 17: error: conio.h: No such file or directory
Line 5: error: expected ';', ',' or ')' before '&' token
In function 'XuatMaTran':
Line 29: error: 'for' loop initial declaration used outside C99 mode
Line 31: error: 'for' loop initial declaration used outside C99 mode
t.c: At top level:
Line 40: error: expected ';', ',' or ')' before '&' token
In function 'HoanVi2Dong':
Line 51: error: 'for' loop initial declaration used outside C99 mode