C++实现双向链表（双向链表的实现）

list是C++容器类中的“顺序存储结构”所包含的一种结构。list是非连续存储结构，具有双链表结构，支持前向/后向遍历，且支持高效的随机删除/插入。

C++实现双向链表（双向链表的实现）

实现代码如下：

**list.h**

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 #pragma once #include<stdio.h> #include<assert.h> #include<iostream> using namespace std; typedef int DataType; struct ListNode { ListNode* _next; ListNode* _prev; DataType _data; ListNode(DataType x) :_data(x) , _next(NULL) , _prev(NULL) {} };

**test.cpp**

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 #define _CRT_SECURE_NO_WARNINGS 1 #include "list.h" class List{ typedef ListNode Node; public: List() :_head(new Node(DataType())){ _head->_next = _head; _head->_prev = _head; } List(const List& l) :_head(new Node(DataType())){ _head->_next = _head; _head->_prev = _head; Node* cur = l._head->_next; while (cur!=l._head){ PushBack(cur->_data); cur = cur->_next; } } List& operator=(const List& l){ if (this != &l){ //swap(_head, l._head); } return *this; } ~List(){ Node* cur = _head->_next; while (cur != _head){ Node* next= cur->_next; delete cur; cur = next; } delete _head; _head = NULL; } void PushBack(DataType x){ Node* prev = _head->_prev; Node* new_node = new Node(x); prev->_next = new_node; new_node->_prev = prev; _head->_prev = new_node; new_node->_next = _head; } void PushFront(DataType x){//插在头结点之后 Node* cur = _head->_next; Node* new_node = new Node(x); new_node->_next = cur; cur->_prev = new_node; new_node->_prev = _head; _head->_next = new_node; } void PopBack(){ Node* delete_node = _head->_prev; Node* cur = delete_node->_prev; _head->_prev = cur; cur->_next = _head; delete delete_node; } void PopFront(){ Node* delete_node = _head->_next; Node* cur = delete_node->_next; _head->_next = cur; cur->_prev = _head; delete delete_node; } Node* Find(DataType x){ Node* to_find = _head->_next; while (to_find != _head){ if (to_find->_data == x){ return to_find; } to_find = to_find->_next; } return NULL; } void Insert(Node* pos, DataType x){//在pos位置前插入数据 assert(pos); Node* new_node = new Node(x); Node* prev = pos->_prev; new_node->_next = pos; pos->_prev = new_node; new_node->_prev = prev; prev->_next = new_node; } void Erase(Node* pos){ assert(pos); Node* prev = pos->_prev; Node* next = pos->_next; prev->_next = next; next->_prev = prev; delete pos; } void Print() const{ Node* cur = _head->_next; cout <<" _head->"; while (cur!= _head){ cout << cur->_data << "->"; cur = cur->_next; } cout << endl; Node* pos = _head->_prev; while (pos != _head){ cout << pos->_data << "<-"; pos = pos->_prev; } cout << "_head" << endl; } private: Node* _head; }; void TestList(){ List L; L.PushBack(1); L.PushBack(2); L.PushBack(4); L.PushBack(5); L.PopBack(); L.Print(); ListNode* pos = L.Find(1); printf("pos->data：%d[%p]\n",pos->_data,pos); pos = L.Find(2); printf("pos->data：%d[%p]\n", pos->_data, pos); pos = L.Find(4); printf("pos->data：%d[%p]\n", pos->_data, pos); printf("\n"); L.Insert(pos, 3); L.Print(); L.Erase(pos); L.Print(); printf("\n"); List L1; L1.PushFront(4); L1.PushFront(3); L1.PushFront(2); L1.PushFront(1); L1.Print(); L1.PopFront(); L1.Print(); } int main(){ TestList(); return 0; }