内容包括链表的创建,增加、删除节点,链表的逆序、排序和销毁等。
- #include<stdio.h>
- #include<stdlib.h>
- typedef struct node
- {
- int data;
- struct node* pNext;
- }Node;
- //链表的操作,以有头节点为例,无头节点类似
- Node* head = NULL;
- //创建链表,头结点data=0,pNext=NULL;
- bool createNodeList()
- {
- head = (Node*) malloc(sizeof(Node));
- if(NULL == head)
- {
- return false;
- }
- else
- {
- head->data = 0;
- head->pNext = NULL;
- return true;
- }
- }
- //增加节点
- bool addNode(Node* node)
- {
- if(NULL == head)
- {
- return false;
- }
- Node* p = head->pNext;
- Node* q = head;
- while(NULL != p)
- {
- q = p;
- p = p->pNext;
- }
- q->pNext = node;
- node->pNext = NULL;
- return true;
- }
- //删除节点
- bool deleteNode(int index)
- {
- if(NULL == head)
- {
- return false;
- }
- Node* p = head->pNext;
- int length = 0;
- while(NULL != p)
- {
- length ++;
- p = p->pNext;
- }
- if(length < index)
- {
- return false;
- }
- else
- {
- Node* q = head;
- p = head;
- for(int i=0;i<index;i++)
- {
- q = p;
- p = p->pNext;
- }
- Node* t = p->pNext;
- q->pNext = t;
- free(p);
- return true;
- }
- }
- //逆序
- void reverseNodeList()
- {
- if(NULL == head)
- {
- return;
- }
- //如果链表长度为1
- if(head->pNext == NULL)
- {
- return;
- }
- Node* p = head->pNext;
- Node* q = p->pNext;
- Node* t = NULL;
- while(NULL != q)
- {
- t = q->pNext;
- q->pNext = p;
- p = q;
- q = t;
- }
- head->pNext->pNext = NULL;
- head->pNext = p;
- }
- //排序(降序)
- void sort()
- {
- //冒泡排序
- Node* pHead = head;
- if(head == NULL)
- {
- return;
- }
- if(pHead->pNext == NULL)
- {
- return;
- }
- Node* pi = pHead->pNext;
- Node* pj = pi->pNext;
- for(;pi != NULL;pi=pi->pNext)
- {
- for(pj = pi->pNext;pj != NULL;pj=pj->pNext)
- {
- if(pj->data>pi->data)
- {
- int tmp = pj->data;
- pj->data = pi->data;
- pi->data = tmp;
- }
- }
- }
- }
- //销毁
- void destroyNodeList()
- {
- if(NULL == head)
- {
- return;
- }
- if(NULL == head->pNext)
- {
- free(head);
- head = NULL;
- return;
- }
- Node* p = head->pNext;
- while(NULL != p)
- {
- Node* tmp = p;
- p = p->pNext;
- free(tmp);
- }
- free(head);
- head = NULL;
- }
- void main()
- {
- createNodeList();
- Node* node1 = (Node*)malloc(sizeof(Node));
- node1->data = 1;
- node1->pNext = NULL;
- Node* node2 = (Node*)malloc(sizeof(Node));
- node2->data = 2;
- node2->pNext = NULL;
- addNode(node1);
- addNode(node2);
- reverseNodeList();
- Node* node3 = (Node*)malloc(sizeof(Node));
- node3->data = 3;
- node3->pNext = NULL;
- addNode(node3);
- sort();
- deleteNode(2);
- destroyNodeList();
- }
关于逆序,以上是非递归过程,还有递归方式,分别详解:
递归算法:
// p 为指向非空单链表中第一个结点的指针,本算法逆转链表并返回逆转后的头指针。基本思路是:如果链表中只有一个结点,则空操作,否则先逆转a2开始的链表,然后将 a1联接到逆转后的链表的表尾(即a2)之后。
LinkList reverse(LinkList p)
{
if(p->next == NULL) return p; // 链表中只有一个结点,逆转后的头指针不变
else
{
q = p->next; // q为链表(a2,…an)的头指针
h = reverse(q); // 逆转链表(a2,…an),并返回逆转后的头指针
q->next = p; // 将a1联接在a2之后
p->next = NULL;
return h; // (a2,…,an)逆转表的头指针即为(a1,a2,…,an)
}
}
- Node* RecReverseList(Node* head) //递归方法
- {
- if (!head || !head->next)
- {
- return head;
- }
- Node *newhead = RecReverseList(head->next);
- head->next->next = head;
- head->next = NULL;
- return newhead;
- }
非递归算法:
- Node* ReverseList(Node* head)
- {
- if (!head || !head->next)
- {
- return head;
- }
- Node* p1 = head;
- Node* p2 = p1->next;
- head->next = NULL;
- while (p2)
- {
- p1 = p2;
- p2 = p2->next;
- p1->next = head;
- head = p1;
- }
- return head;
- }