数据结构常用函数（一）

待我称王封你为后i 2022-05-27 10:08 251阅读 0赞

数据结构中，我们经常用到了一些操作，比如删除，插入等等，有API函数直接调用，当然是比较好的，但是我们可以尝试一下自己写一下代码。  
以简单的录入个人信息为例，首先来看一下这些函数。

#include <stdlib.h>
    
    typedef struct
    {
        char key[15];
        char name[20];
        int age;
    }DATA;
    
    typedef struct Node{
        DATA data;
        struct Node *next;
    }ChainListType;
    
    ChainListType *ChainListAddEnd(ChainListType *head,DATA data);
    ChainListType *ChainListAddFirst(ChainListType *head,DATA data);
    ChainListType *ChainListFind(ChainListType *head,char *key);
    ChainListType *ChainListInsert(ChainListType *head,char *findkey,DATA data);
    int ChainListDelete(ChainListType *head,char *key);
    int ChainListLength(ChainListType *head); 
    void ChainlistPrintAll(ChainListType *head);

现在我们就来一步一步的实现每一个函数  
1.遍历链表

void ChainlistPrintAll(ChainListType *head)
    {
        ChainListType *h;
        DATA data;
        h=head;
        printf("list as fllowing:\n");
        while(h){
       //处理每一个节点
            data=h->data;
            printf("(%s,%s,%d)\n",data.key,data.name,data.age);
            h=h->next;//准备处理下一个节点
        }
        return ;
    }

2.链表元素个数

int ChainListLength(ChainListType *head)
    {
        ChainListType *h;
        int i=0;
        h=head;
        while(h){
            i++;
            h=h->next;//遍历计数
        }
        return i;
    }

3.删除某个节点

int ChainListDelete(ChainListType *head,char *key)
    {
            ChainListType *node,*h;
            node=h=head;
            while(h){
                if(strcmp(h->data.key,key)==0){
       //找关键字
                    node->next=h->next;
                    free(h);//释放内存
                    return 1;
                }else{
                    node=h;
                    h=h->next;//没找到就接着找
                }
            }
            return 0;
    }

4.插入某个元素

ChainListType *ChainListInsert(ChainListType *head,char *findkey,DATA data)
    {
        ChainListType *node,*node1;
        if(!(node=(ChainListType *)malloc(sizeof(ChainListType))))
        {
            printf("node's application fail!\n");
            return 0;
        }
        node->data=data;
        node1=ChainListFind(head,findkey);
        if(node1){
            node->next=node1->next;
            node1->next=node;
        }else{
            free(node);
            printf("do not find the place!\n");
        }
    }

5.查找某个元素

ChainListType *ChainListFind(ChainListType *head,char *key)
    {
        ChainListType *h;
        h=head;
        while(h){
       //节点有效
            if(strcmp(h->data.key,key)==0)
                return h;
            h=h->next;
        }
        return NULL;
    }

6.添加头节点

ChainListType *ChainListAddFirst(ChainListType *head,DATA data)
    {
        ChainListType *node,*h;
        if(!(node=(ChainListType *)malloc(sizeof(ChainListType))))
        {
            printf("node's application fail!\n");
            return NULL;
        }
        node->data=data;
        node->next=head;
        head=node;
        return head;
    }

7.添加尾节点

ChainListType *ChainListAddEnd(ChainListType *head,DATA data)
    {
        ChainListType *node,*h;
        if(!(node=(ChainListType *)malloc(sizeof(ChainListType))))
        {
            printf("node's application fail!\n");
            return NULL;
        }
        node->data=data;
        node->next=NULL;
        if(head==NULL){
            head=NULL;
            return head;
        }
        h=head;
        while(h->next!=NULL)
            h=h->next;
        h-next=node;
        return head;
    }

我们可以来写一个函数来测试一下

#include <iostream>
    #include <string.h>
    #include "ChainList_API.h"
    
    /* run this program using the console pauser or add your own getch, system("pause") or input loop */
    
    int main(int argc, char** argv) 
    {
        ChainListType *node,*head=NULL;
        DATA data;
        char key[15],findkey[15];
    
        printf("Enter the data in the linked list, including keywords, names, age：\n");
    
        do{
            fflush(stdin);
            scanf("%s",data.key);
            if(strcmp(data.key,"0")==0) break;
            scanf("%%d",data.name,data.age);
            head=ChainListAddEnd(head,data);
        }while(1);
    
        printf("The number of nodes in the linked list is:%d\n",ChainListLength(head));
        ChainlistPrintAll(head);
    
        printf("\nEnter the insertion node's keyword:\n");
        scanf("%s",&findkey);
        printf("Enter the data in the linked list, including keywords, names, age：\n");
        scanf("%s%s%d",data.key,data.name,data.age);
        head=ChainListInsert(head,findkey,data);
    
        ChainlistPrintAll(head);
    
        printf("Enter search keywords:\n");
        fflush(stdin);
        scanf("%s",key);
        node=ChainListFind(head,key);
        if(node){
            data=node->data;
            printf("The keyword %s corresponding node is:(%s,%s,%d)",key,data.key,data.name,data.age);
        }else
            printf("No corresponding node found!\n");
    
        printf("Enter keywords to delete:\n");
        fflush(stdin);
        scanf("%s",key);
        ChainListDelete(head,key);
    
        ChainlistPrintAll(head);
    
        return 0;
    }

这里是文件，这个是**[ChainList\_API.c][ChainList_API.c]**文件，这个是**[ChainList\_API.h][ChainList_API.h]**文件。

[ChainList_API.c]: https://download.csdn.net/download/klaus_x/10353398
[ChainList_API.h]: https://download.csdn.net/download/klaus_x/10353404