#include "Header.h"

QLKH::QLKH()
{
	pHead = pTail = NULL;
}
QLKH::~QLKH()
{
	Node* temp;
	while (pHead != NULL)
	{
		temp = pHead;
		pHead = pHead->pNext;
		delete temp;
	}
}
Node* QLKH::getNode(const Student& x)
{
	Node* p = new Node;

	if (p == NULL)
	{
		cout << "Khong du bo nho. \n";
		return NULL;
	}

	p->Data = x;
	p->pNext = NULL;
	return p;
}
void QLKH::PushBack(const Student& x)
{
	Node* p = getNode(x);
	if (pHead == NULL)
	{
		pHead = pTail = p;
	}
	else
	{
		pTail->pNext = p;
		pTail = p;
	}
}
void QLKH::CalculateGrade(Student& x)
{
	if (x.score < 50)
		x.grade = 'F';
	else if (x.score < 60)
		x.grade = 'D';
	else if (x.score < 70)
		x.grade = 'C';
	else if (x.score < 80)
		x.grade = 'B';
	else
		x.grade = 'A';
}
istream& operator>>(istream& in, Student& x)
{
	in >> x.id;
	in >> x.name;
	in >> x.score;
	
	return in;
}
ostream& operator<<(ostream& out, Student x)
{
	out << x.id << "\t" << x.name << "\t" << x.score << "\t" << x.grade;

	return out;
}
void QLKH::Print()
{
	cout << "id\t name\t score\t grade\t";
	for (Node* p = pHead; p != NULL; p = p->pNext)
	{
		cout << p->Data;
	}
}