实验三 双链表

#include<iostream> using namespace std; typedef int DataType; struct DouNode { DataType data; struct DouNode * prior,* next; }; class Student { public: Student(); Student(DataType a[],int n); ~Student(); int Length(); int Get(int i); void Insert(int i,DataType x); DataType Delete(int i); void Print(); private: struct DouNode *first; }; Student::Student() { first=new DouNode; first->next=NULL; } Student::Student(DataType a[],int n) { struct DouNode *s; first=new DouNode; first->next=NULL; for(int i=0;i<n;i++) { s=new DouNode; s->data=a[i]; s->next=first->next; first->next=s; } }

Student::~Student() { struct DouNode *q; while(first!=NULL) { q=first; first=first->next; delete q; } } DataType Student::Delete(int i) { struct DouNode *p,*q; p=first; int count=0,x; while(p!=NULL&&count<i-1) { p=p->next; count++; } if(p==NULL||p->next==NULL) cout<<"位置非法"<<endl; else { q=p->next; x=q->data; p->next=q->next; (q->next)->prior=p->prior; delete q; return x; } return 0; }

void Student::Print() {      DouNode *p;      int i=0;          p=first->next;      while(p!=NULL)      {             i=i+1;           cout<<"第"<<i<<"个学生成绩:"<<p->data<<endl;         p=p->next;      }  } int Student::Length() { struct DouNode *p; p=first->next; int count=0; while(p!=NULL) { p=p->next; count++; } return count; } int Student::Get(int i) { struct DouNode *p; p=first->next; int count=1; while(p!=NULL&&count<i) { p=p->next; count++; } if(p==NULL) cout<<"位置非法"<<endl; else return p->data; } void Student::Insert(int i,DataType x) { struct DouNode *p; p=first; int count=0; while(p!=NULL&&count<i-1) { p=p->next; count++; } if(p==NULL) cout<<"位置非法"<<endl; else { DouNode *s;         s=new DouNode;  s->data=x;    s->prior=p; s->next=p->next; p->next->prior=s; p->next=s; } } void main() { int score[3]={98,90,95}; Student S(score,3); cout<<"学生的成绩为："<<endl; S.Print(); cout<<endl<<endl<<"在位置2插入成绩70："<<endl; S.Insert(2,70); S.Print(); cout<<endl<<endl<<"删除位置1的成绩："<<endl; S.Delete(1); S.Print(); cout<<endl<<endl<<"位置3的成绩为："<<endl; cout<<S.Get(3)<<endl; cout<<endl; }