So Dao Nguoc

#include <iostream>
#define MAX 1000000
using namespace std;
void nhapsonguyenduong(int &n)
{
	do
	{
		cout << "nhap so nguyen duong de kiem tra = ";
		cin >> n;
		if (n<0 || n>MAX)
		{
			cout << " so khong hop le, xin moi nhap lai";
		}
	} while ((n < 0) || (n > MAX));

}
int sodaonguoc(int &n)
{
	int daonguoc = 0;
	int phantu;
	while (n > 0)
	{
		phantu = n % 10;
		daonguoc = daonguoc * 10 + phantu;
		n = n / 10;
	}
	return daonguoc;
}
void main()
{
	int n;
	nhapsonguyenduong(n);
	cout << "so dao nguoc la: " << sodaonguoc(n) << endl;
	system("pause");
}