反转链表（C++实现）

#include <iostream>

//迭代法
class Node{
public:
  int value;
  Node* next;
  Node(int data){
    this->value = data;
  }
} ;

Node* reverseNode(Node* head)
{
  Node* pre = head;

  Node* cur = NULL;

  while(pre!=NULL)
  {

    Node* tem = pre->next;

    pre->next = cur;

    cur = pre;

    pre = tem;

  }
  return cur;
}

//递归法
Node* d_reverseNode(Node* head)
{

  if(head==NULL||head->next==NULL)
  {
    return head;
  }

  Node* tem = d_reverseNode(head->next);
  head->next->next = head;
  head->next = NULL;
  return tem;

}

int main()
{

Node* node1 = new Node(1);
Node* node2 = new Node(2);

Node* node3 = new Node(3);
Node* node4 = new Node(4);

Node* node5 = new Node(5);
Node* head = node1;
head->next = node2;
node2->next = node3;
node3->next = node4;
node4->next = node5;

node5->next = NULL;
Node* cur = head;
while(cur!=nullptr){

  std::cout << cur->value << ' ';
  cur = cur->next;

}

Node* t = reverseNode(head);
Node* tem = t;
std::cout  << '\n';

while(t!=nullptr)
{
  std::cout << t->value << ' ';
  t = t->next;
}
std::cout  << '\n';
Node* t_1 = d_reverseNode(tem);

while(t_1!=nullptr)
{
  std::cout << t_1->value << ' ';
  t_1 = t_1->next;
}
}

 

测试结果：