链表删除和显示问题！

#include "Student.h"

#include <iostream>

#include <string>

using namespace std;

typedef struct ListNode

{

	string sID;

	string sName;

	string bSex;

	double Score[2];

	ListNode* pNext;

}Node;



class StudentList

{

	Node* pHead;

	Node* pNew;

	Node* pTail;

public:

	StudentList(){pHead=NULL;};

	Node* ReadStudent(StudentList &list);

	void DeleteStudent();

	void ShowStudent(StudentList &list);

	Node* SelectStudent();

	Node* SearchStudent();

};



void StudentList::ShowStudent(StudentList &list)

{

	cout<<"ID		"<<"Name		"<<"Sex		"<<"English		"<<"Math"<<endl;

	Node* p=pHead;

	while(p!=NULL)

	{

		cout<<p->sID<<"		"<<p->sName<<"		"<<p->bSex<<"		"

			<<p->Score[0]<<"		"<<p->Score[1]<<endl;

		p=p->pNext;

	}

}



void StudentList::DeleteStudent()

{

	string ID;

	cout<<"Please input the student's ID"<<endl;

	cin>>ID;

	Node* pPre;

	Node* p=pHead;

	while(p!=NULL)

	{

		pPre=p;

		if(ID==p->sID)//因为学号唯一，所以查找到后直接删除，不用继续查找

		{

			pPre->pNext=p->pNext;

			delete p;

			cout<<"删除成功！"<<endl;

			return;

		}

		p=p->pNext;

	}

	cout<<"不存在些学号的学生纪录"<<endl;

}