#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 SapXepCheoPhuGiamDan(int a[][MAX], int n)
{
	for(int i = 0; i < n; i++)
	{
		for(int j = i + 1; j < n; j++)
		{
			int max = a[i][n - 1 - i];
			if(a[j][j - 1 - i] > max)
			{
				max = a[j][n - 1 - j];
                a[j][n - 1 - j] = a[i][n - 1 - i];
                a[i][n - 1 - i] = max;  
			}
		}
	}
}

int main()
{
	int a[MAX][MAX], n;
	NhapMaTran(a,n);
	XuatMaTran(a,n);
	SapXepCheoPhuGiamDan(a, n);
	printf("\nSap xep duong cheo phu giam dan: \n");
	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
In function 'SapXepCheoPhuGiamDan':
Line 42: error: 'for' loop initial declaration used outside C99 mode
Line 44: error: 'for' loop initial declaration used outside C99 mode