双向链表的三个重要组成部分：
1.数据域
2.前指针域
3.后指针域
基本操作：
1.初始化列表
2.前插法
3.后插法
4.任意位置插入
5.删除元素
感想:与单链表的区别的就是多了一个前指针.其他的没有太大的变化
1.初始化:
typedef struct DBLink {
int date;
struct DBLink* prew;
struct DBLink* next;
}DBLinkList, DBLinkNode;
bool Dbinit_Link(DBLinkList*& L) {
//初始化
L = new DBLinkList;
if (!L) return false;
L->date = -1;
L->next = NULL;
L->prew = NULL;
return true;
}
2.前插法:
如果是没有元素,那么就使头结点指向新节点
新节点的前指针指向头结点
如果已经有了其他的元素了，那么就使新元素的尾指针指，向头节点原来指向的节点,让头节点指向新节点
再是原来的第二个节点的头节点指向新节点,新节点的前指针指向头节点
bool DbLinkInserct_front(DBLinkList*& L, DBLinkNode* s) {
if (!L || !s) return false;
if (L->next == NULL) {
L->next = s;
s->prew = L;
s->next = NULL;
}
else {
s->next = L->next;
L->next = s;
s->next->prew = s;
s->prew = L;
}
return true;
}
3.后插法
bool DbLinkInserct_back(DBLinkList*& L, DBLinkNode* s) {
if (!L || !s) return false;
DBLinkNode* p;
p = L;
while (p->next != NULL) {
p = p->next;
}
p->next = s;
s->prew = p;
s->next = NULL;
return true;
}
4.任意插入:
bool DbLinkInserct(DBLinkList*& L, int index, DBLinkNode* s) {
if (!L || !s) return false;
int i = 0;
DBLinkList* p = L;
while (p && i < index) {
p = p->next;
i++;
}
if (!p) return false;
p->prew->next = s;
s->next = p;
s->prew = p->prew;
p->prew = s;
return true;
}
5.删除元素:
bool DbLinkDelete(DBLinkList*& L, int index) {
if (!L) return false;
int i = 1;
DBLinkList* p = L->next;
DBLinkNode* q = NULL;
while (p && i < index) {
p = p->next;
i++;
}
p->prew->next = p->next;
if (p->next)
p->next->prew = p->prew;
delete p;
return true;
}
全部源代码;
#include<Windows.h>
#include<iostream>
using namespace std;
typedef struct DBLink {
int date;
struct DBLink* prew;
struct DBLink* next;
}DBLinkList, DBLinkNode;
bool Dbinit_Link(DBLinkList*& L) {
//初始化
L = new DBLinkList;
if (!L) return false;
L->date = -1;
L->next = NULL;
L->prew = NULL;
return true;
}
bool DbLinkInserct_front(DBLinkList*& L, DBLinkNode* s) {
if (!L || !s) return false;
if (L->next == NULL) {
L->next = s;
s->prew = L;
s->next = NULL;
}
else {
s->next = L->next;
L->next = s;
s->next->prew = s;
s->prew = L;
}
return true;
}
bool DbLinkInserct_back(DBLinkList*& L, DBLinkNode* s) {
if (!L || !s) return false;
DBLinkNode* p;
p = L;
while (p->next != NULL) {
p = p->next;
}
p->next = s;
s->prew = p;
s->next = NULL;
return true;
}
bool DBLink_print(DBLinkList*& L) {
DBLinkNode* p = NULL;
p = L->next;
while (p) {
cout << p->date << "\t";
p = p->next;
}
cout << endl;
return 0;
}
bool DbLinkInserct(DBLinkList*& L, int index, DBLinkNode* s) {
if (!L || !s) return false;
int i = 0;
DBLinkList* p = L;
while (p && i < index) {
p = p->next;
i++;
}
if (!p) return false;
p->prew->next = s;
s->next = p;
s->prew = p->prew;
p->prew = s;
return true;
}
bool DbLinkDelete(DBLinkList*& L, int index) {
if (!L) return false;
int i = 1;
DBLinkList* p = L->next;
DBLinkNode* q = NULL;
while (p && i < index) {
p = p->next;
i++;
}
p->prew->next = p->next;
if (p->next)
p->next->prew = p->prew;
delete p;
return true;
}
void DBLink_Destroy(DBLinkList*& L) {
DBLinkNode* p = L;
cout << "销毁链表!" << endl;
while (L) {
L = L->next;
delete p;
p = L;
}
}
int main() {
DBLinkList* L;
DBLinkNode* s;
int n;
Dbinit_Link(L);
//1.前插法
cout << "输入要前插入的数据个数:" << endl;
cin >> n;
while (n) {
s = new DBLinkNode;
cout << "请输入要插入的数据:";
cin >> s->date;
if (DbLinkInserct_front(L, s)) {
cout << "插入成功!" << endl;
}
else {
cout << "插入失败!" << endl;
}
n--;
}
//2.输出
DBLink_print(L);
/*x
//3.后插法
cout << "输入要后插入的数据个数:" << endl;
cin >> n;
while (n) {
s = new DBLinkNode;
cout << "请输入要插入的数据:";
cin >> s->date;
if (DbLinkInserct_back(L, s)) {
cout << "插入成功!" << endl;
}
else {
cout << "插入失败!" << endl;
}
n--;
}
DBLink_print(L);
*/
//4.任意位置插入
int pos;
cout << "要插入的个数:";
cin >> n;
while (n) {
s = new DBLinkNode;
cout << "输入要插入的位置和元素:";
cin >> pos >> s->date;
if (DbLinkInserct(L, pos, s)) {
cout << "插入成功!" << endl;
DBLink_print(L);
}
else {
cout << "插入失败!" << endl;
}
n--;
}
//5.删除元素
cout << "输入要删除的元素的位置:";
cin >> n;
if (DbLinkDelete(L, n)) {
cout << "删除成功!" << endl;
}
else {
cout << "删除失败!" << endl;
}
DBLink_print(L);
DBLink_Destroy(L);
system("pause");
return 0;
}