在双向链表中删除倒数第K个链表节点（C++实现）

代码：

#include <iostream>

class DoubleNode{
public:

  int value;

  DoubleNode* last;

  DoubleNode* next;

  DoubleNode(int data){

    this->value = data;

  }
};

DoubleNode* removeLastKthNode(DoubleNode*head,int lastKth){

  if(head == nullptr || lastKth < 1){

    return head;

  }

  DoubleNode* cur = head;

  while(cur!=nullptr)
  {
    lastKth--;
    cur = cur->next;
  }

  if(lastKth==0){

    head = head->next;

    head->last = nullptr;
  }

  if(lastKth < 0)
  {
    cur = head;
    while(++lastKth != 0){

      cur = cur->next;

    }

    cur->next = cur->next->next;

    if(cur->next->next!=nullptr){

      cur->next->next->last = cur;

    }
  }
  return head;
}
int main()
{

DoubleNode* node1 = new DoubleNode(1);

DoubleNode* node2 = new DoubleNode(2);

DoubleNode* node3 = new DoubleNode(3);

DoubleNode* head = node1;

node1->last = head;

node1->next = node2;

node2->last = node1;

node2->next = node3;

node3->last = node2;

node3->next = NULL;

DoubleNode* cur = head;

while(cur!=nullptr){

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

}

removeLastKthNode( head,2);

std::cout  << ' ';

DoubleNode* tem = head;

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

}

 

测试结果：