算法（16）链表-单链表-双链表-逆序-C++代码

单链表，双向链表实现逆序，C++代码，供大家参考。
一般Node用struct定义，我这用的class.
void reverseList_main()为主函数。

class Node {
public:
    int m_value;
    Node *next;
    //构造函数
    Node(int value);
};
Node::Node(int value)
{
    m_value = value;
}
class doubleNode {
public:
    int m_value;
    doubleNode *next;
    doubleNode *last;
    doubleNode(int value);
};
doubleNode::doubleNode(int value)
{
    m_value = value;
}




void printLinkedList(Node *head) 
{   
    while (head != nullptr)
    {       
        cout << "head.value= " << head->m_value <<endl;
        head = head->next;
    }

}
void printDLinkedList(doubleNode* head)
{
    while (head != nullptr)
    {
        cout << "head.value= " << head->m_value << endl;
        head = head->next;
    }

}

// 后往前 next head1 pre
Node* reverseList(Node* head) {
    Node* pre = nullptr;
    Node* next = nullptr;
    while (head!= nullptr) {
        next = head->next;
        head->next = pre;
        pre = head;
        head = next;
    }
    return pre;

}

doubleNode* reverseDList(doubleNode * head)
{
    doubleNode* pre = nullptr;
    doubleNode* next = nullptr;
    while (head != nullptr) {
        next = head->next;
        head->next = pre;
        head->last = next;
        pre = head;
        head = next;
    }
    return pre;
}


//主函数
void reverseList_main()
{
    cout << "reverseList *************" << endl;
    Node* pnode1 = new Node(7);
    Node* pnode2 = new Node(8);
    Node* pnode3 = new Node(9);
    Node* pnode4 = new Node(10);
    pnode1->next = pnode2;
    pnode1->next->next = pnode3;
    pnode1->next->next->next = pnode4;
    printLinkedList(pnode1);
    Node* rcp=reverseList(pnode1);
    printLinkedList(rcp);


    cout << "reverseDList *************" << endl;
    doubleNode* pDnode1 = new doubleNode(11);
    doubleNode* pDnode2 = new doubleNode(22);
    doubleNode* pDnode3 = new doubleNode(33);
    doubleNode* pDnode4 = new doubleNode(44);


    pDnode1->next = pDnode2;
    pDnode1->next->next = pDnode3;
    pDnode1->next->next->next = pDnode4;
    printDLinkedList(pDnode1);
    doubleNode* rcdp = reverseDList(pDnode1);
    printDLinkedList(rcdp);

     delete  pnode1 ;
     delete  pnode2 ;
     delete  pnode3 ;
     delete  pnode4 ;

     delete  pDnode1;
     delete  pDnode2;
     delete  pDnode3;
     delete  pDnode4;



}