KT So Doi Xung

#include <iostream>
#define MAX 100000
using namespace std;
void nhapsonguyenduong(int &n)
{
	do
	{
		cout << "nhap so vao de kiem tra = ";
		cin >> n;
		if ((n < 0) || (n > MAX))
		{
			cout << "so khong hop le , kiem tra lai";
		}
	} while ((n < 0) || (n > MAX));
}
int ktsodoixung(int &n)
{
	int doixung = 0;
	int temp = n;
	int phantu;
	while (n > 0)
	{
		phantu = n % 10;
		doixung = doixung * 10 + phantu;
		n = n / 10;
	}
	if (doixung == temp)
		return true;
	else
		return false;
}
void main()
{
	int n;
	nhapsonguyenduong(n);
	if (ktsodoixung(n) == true)
		cout << " day la so doi xung" << endl;
	else
		cout <<" day khong phai la doi xung " << endl;
	system("pause");
}