数据结构：（1）线性表

一、基本概念 

概念：零个或多个数据元素的有限序列
    
    元素之间是有顺序了。如果存在多个元素，第一个元素无前驱，最后一个没有后继，其他的元素只有一个前驱和一个后继。
    
    当线性表元素的个数n（n>=0）定义为线性表的长度，当n=0时，为空表。在非空的表中每个元素都有一个确定的位置，如果a1是第一个元素，那么an就是第n个元素。

线性表的常规操作  ADT
typedef struct person {
    char name[32];
    char sex;
    int age;
    int score;
}DATATYPE;
//typedef int Datatype;

typedef struct list {
    DATATYPE *head;//数组名
    int tlen;//数组有多大
    int clen;//当前存储了几个元素
}SeqList;

---

例：

1.SeqList *CreateSeqList(int len);
2.int DestroySeqList(SeqList *list);
3.int ShowSeqList(SeqList *list);
4.int InsertTailSeqList(SeqList *list, DATATYPE data);
5.int IsFullSeqList(SeqList *list);
6.int IsEmptySeqList(SeqList *list);
7.int InsertPosSeqList(SeqList *list, DATATYPE data, int pos);
8.int FindSeqList(SeqList *list, char *name);
9.int ModifySeqList(SeqList *list, char *old, DATATYPE new);
10.int DeleteSeqList(SeqList *list, char *name);
11.int ClearSeqList(SeqList *list);

内存泄露检测工具
sudo apt-get install valgrind
valgrind ./all

1. CreateSeqList 创建表

SeqList *CreateSeqList(int size)
{
    if(size<=0)
    {
        fprintf(stderr,"size is error,range >1");
        return NULL;
    }
    SeqList* sl = ( SeqList*)malloc(sizeof(SeqList));
    if(NULL == sl)
    {
        perror("CreateSeqList malloc");
        exit(1);
    }
 
    sl->head = (DATATYPE*)malloc(sizeof(DATATYPE)*size);
    if(NULL == sl->head)
    {
        perror("CreateSeqList malloc");
        exit(1);
    }
 
    sl->tlen = size;
    sl->clen = 0;
    return sl;
}

2. DestroySeqList 销毁表

int DestroySeqList(SeqList *sl)
{
    if(NULL == sl)
    {
        fprintf(stderr,"SeqList point not NULL");
        return 1;
    }
    if(sl->head)
        free(sl->head);
    free(sl);
    return 0;
}

3. ShowSeqList 遍历表，打印内容

int ShowSeqList(SeqList *list)
{
    if(NULL == list)
    {
        fprintf(stderr,"list error,list is null\n");
        return -1;
    }
    int i = 0 ;
    int len = GetSizeSeqList(list);
    for(i=0;i<len;i++)
    {
        printf("name:%s sex:%c age:%d score:%d\n",list->head[i].name,list->head[i].sex,list->head[i].age
               ,list->head[i].score);
    }
    return 0;
}

4. InsertTailSeqList 尾插

int InsertTailSeqList(SeqList *list, DATATYPE *data)
{
    if(NULL == list)
    {
        fprintf(stderr,"InsertTailSeqList error,list is null\n");
        return -1;
    }
 
    if(IsFullSeqList(list))
    {
        fprintf(stderr,"InsertTailSeqList error ,seqlist is full\n");
        return 1;
    }
    memcpy(&list->head[list->clen] , data,sizeof(DATATYPE));
    list->clen++;
    return 0;
}

5. IsFullSeqList 表满判断

int IsFullSeqList(SeqList *list)
{
    if(NULL == list)
    {
        fprintf(stderr,"IsFullSeqList error,list is null\n");
        return -1;
    }
    return list->clen == list->tlen;
}

6. IsEmptySeqList 表空判断

int IsEmptySeqList(SeqList *list)
{
    return 0==list->clen;
}

7. InsertPosSeqList 任意位置插入

int InsertPosSeqList(SeqList *list, DATATYPE *data, int pos)
{
    if(NULL == list)
    {
        fprintf(stderr,"list is null\n");
        return 1;
    }
    if(IsFullSeqList(list))
    {
        fprintf(stderr,"list is full\n");
        return 1;
    }
    if(pos<0 ||pos>GetSizeSeqList(list))
    {
        fprintf(stderr,"pos is error\n");
        return 1;
    }
 
    int i = 0 ;
 
    for(i =GetSizeSeqList(list); i>=pos ; i-- )
    {
        memcpy(&list->head[i],&list->head[i-1],sizeof(DATATYPE));
 
    }
    memcpy(&list->head[pos],data,sizeof(DATATYPE));
    list->clen++;
    return 0;
}

8. FindSeqList 查找表内某个内容，返回其下标

int FindSeqList(SeqList *list, char *name)
{
    if(NULL == list)
    {
        fprintf(stderr,"FindSeqList error,list is null\n");
        return 1;
    }
    if(IsEmptySeqList(list))
    {
        fprintf(stderr,"FindSeqList error,seqlist is empty\n");
        return -1;
    }
    int len = GetSizeSeqList(list);
    int i = 0 ;
    for(i=0;i<len;i++)
    {
        if(0==strcmp(list->head[i].name,name))
        {
            return i;
        }
    }
    return -1;
}

9. ModifySeqList 修改表内某个内容

int ModifySeqList(SeqList *list, char *old, DATATYPE *newdata)
{
    if(NULL == list)
    {
        fprintf(stderr,"ModifySeqList error,list is null\n");
        return 1;
    }
    int ret = FindSeqList(list,old);
    if(-1 == ret)
    {
        fprintf(stderr,"modify error,can't find\n");
        return 1;
    }
    DATATYPE* tmp = GetSeqListItem(list,ret);
    memcpy(tmp,newdata,sizeof(DATATYPE));
    return 0;
}

10. DeleteSeqList 删除表的内容

int DeleteSeqList(SeqList *list, char *name)
{
    if(NULL == list)
    {
        fprintf(stderr,"DeleteSeqList error,list is null\n");
        return 1;
    }
    int ret = FindSeqList(list,name);
    if(-1 == ret)
    {
        return 1;
    }
    else
    {
        int i = 0 ;
        for(i =ret; i <GetSizeSeqList(list)-1 ; i++)
        {
            memcpy(&list->head[i] ,&list->head[i+1],sizeof(DATATYPE));
        }
    }
 
    list->clen--;
    return 0 ;
}

11. ClearSeqList 把表清空

int CleanSeqList(SeqList *list)
{
    if(NULL == list)
    {
        fprintf(stderr,"CleanSeqList error,list is null\n");
        return 1;
    }
    list->clen = 0 ;
    return 0;
}

main.c 

#include <stdio.h>
#include "seqlist.h"
int main()
{
    SeqList* sl = CreateSeqList(10);
 
    DATATYPE data[5]={
        {"zhangsan",'m',20,70},
        {"lisi",'f',21,60},
        {"wangmazi",'m',25,80},
        {"liubei",'f',30,85},
        {"caocao",'f',40,90},
    };
    InsertTailSeqList(sl,&data[0]);
    InsertTailSeqList(sl,&data[1]);
    InsertTailSeqList(sl,&data[2]);
    printf("----------------show------------------\n");
    ShowSeqList(sl);
    printf("----------------find------------------\n");
        char find_name[50]="lisi";
        int ret = FindSeqList(sl,find_name);
        if(-1 == ret)
        {
            printf("can't find person ,%s\n",find_name);
        }
        else
        {
           DATATYPE* tmp   =  GetSeqListItem(sl,ret) ;
           printf("name:%s score:%d\n",tmp->name,tmp->score);
        }
    printf("----------------pos------------------\n");
    InsertPosSeqList(sl,&data[3],3);
    ShowSeqList(sl);
    printf("----------------modify------------------\n");
    ModifySeqList(sl,"li1si",&data[4]);
    ShowSeqList(sl);
    printf("----------------delete------------------\n");
    DeleteSeqList(sl,"zhangsan");
    ShowSeqList(sl);
    DestroySeqList(sl);
    printf("Hello World!\n");
    return 0;
}

 

 

二、线性表顺序存储的优点、缺点

优点

1.无需为表中的逻辑关系增加额外的存储空间
2.可以快速随机访问元素，时间复杂度-->O(1)，效率高 

缺点

1.插入，删除元素需要移动元素，时间复杂度-->O(n)，效率较低
2.无法动态存储