数据结构-单链表

一. 带head单链

    1.1. 什么是head单链

    1.2. 单链创建

listNode_t *CreatList(int listLen)
{
    listNode_t *head = malloc(sizeof(listNode_t));
    listNode_t *temp = head;
    temp->next = NULL;
    temp->data = 0;

    for (int i = 1; i < listLen; i++)
    {
        listNode_t *ptr = malloc(sizeof(listNode_t));
        ptr->next = NULL;
        ptr->data = i;
        temp->next = ptr;
        temp = temp->next;
    }
    return head;
}

    1.3. 单链插入

listNode_t *InsertNode(listNode_t *head, int index, int data)
{
    if (head == NULL)
        return NULL;
    listNode_t *node = head;
    for (int i = 0; i<index-1; i++)
    {
        if(NULL == node->next)
        {
            printf("%s|%d: can't find index=%d node\r\n", __func__, __LINE__, index);
            return NULL;
        }
        node = node->next;
    }
    listNode_t *newNode = CreatList(1);
    newNode->data = data;
    newNode->next = node->next;
    node->next = newNode;
    return head;
}

 

    1.4. 单链删除

listNode_t *DeleteNode(listNode_t *head, int index)
{
    if (head == NULL)
        return NULL;
    listNode_t *node = head;
    listNode_t *delNode;
    for(int i=0;i<index-1;i++)
    {
        if(NULL==node->next)
        {
            printf("%s|%d: can't find index=%d node\r\n", __func__, __LINE__, index);
            return NULL;
        }
        node = node->next;
    }
    delNode = node->next;
    node->next=delNode->next;
    free(delNode);
    return head;
}

 

    1.5. 寻找中间节点

listNode_t *FindNodeMid(listNode_t *const head)
{
    if (head == NULL)
        return NULL;
    listNode_t *fastNode=head;
    listNode_t *slowNode=head;
    while(fastNode->next!=NULL&&fastNode->next->next!=NULL)
    {
        fastNode=fastNode->next->next;
        slowNode=slowNode->next;
    }
    return slowNode;
}

    1.6. 完整示例

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

typedef struct listNode
{
    int data;
    struct listNode *next;
} listNode_t;

listNode_t *CreatList(int listLen)
{
    listNode_t *head = malloc(sizeof(listNode_t));
    listNode_t *temp = head;
    temp->next = NULL;
    temp->data = 0;

    for (int i = 1; i < listLen; i++)
    {
        listNode_t *ptr = malloc(sizeof(listNode_t));
        ptr->next = NULL;
        ptr->data = i;
        temp->next = ptr;
        temp = temp->next;
    }
    return head;
}

listNode_t *InsertNode(listNode_t *head, int index, int data)
{
    if (head == NULL)
        return NULL;
    listNode_t *node = head;
    for (int i = 0; i<index-1; i++)
    {
        if(NULL == node->next)
        {
            printf("%s|%d: can't find index=%d node\r\n", __func__, __LINE__, index);
            return NULL;
        }
        node = node->next;
    }
    listNode_t *newNode = CreatList(1);
    newNode->data = data;
    newNode->next = node->next;
    node->next = newNode;
    return head;
}
listNode_t *DeleteNode(listNode_t *head, int index)
{
    if (head == NULL)
        return NULL;
    listNode_t *node = head;
    listNode_t *delNode;
    for(int i=0;i<index-1;i++)
    {
        if(NULL==node->next)
        {
            printf("%s|%d: can't find index=%d node\r\n", __func__, __LINE__, index);
            return NULL;
        }
        node = node->next;
    }
    delNode = node->next;
    node->next=delNode->next;
    free(delNode);
    return head;
}

listNode_t *FindNodeMid(listNode_t *const head)
{
    if (head == NULL)
        return NULL;
    listNode_t *fastNode=head;
    listNode_t *slowNode=head;
    while(fastNode->next!=NULL&&fastNode->next->next!=NULL)
    {
        fastNode=fastNode->next->next;
        slowNode=slowNode->next;
    }
    return slowNode;
}
static bool GetNode(listNode_t *head,int index, int *pData)
{
    bool ret = false;
    if(NULL == head)
        return ret;
    listNode_t *node = head;
    for(int i=0;i!=index;i++)
    {
        if(NULL==node->next)
        {
            printf("%s|%d: can't find index=%d node\r\n", __func__, __LINE__, index);
            return false;
        }
        node = node->next;
    }
    *pData = node->data;
    ret=true;
    return ret;
}
bool selectNode(listNode_t *head, const int data,int *pIndex)
{
    bool ret = false;
    if(NULL == head)
        return ret;
    int i=0;
    listNode_t *node = head;
    while(node->next!=NULL)
    {
        if(node->data == data)
        {
            *pIndex=i;
            ret=true;
        }
        node=node->next;
    }
    return ret;
}

int main(char argc, char *argv[])
{
    listNode_t *head = CreatList(5);
    listNode_t *midNode=NULL;
    InsertNode(head, 1, 6);
    DeleteNode(head, 1);
    int data;
    if(true == GetNode(head,1,&data))
        printf("node  data:%d\r\n",data);
    midNode = FindNodeMid(head);
    if(NULL != midNode)
        printf("mid node data:%d\r\n",midNode->data);    
    return 0;
}