用c语言写线性表的基本操作

线性表是一种常见的数据结构，C语言可以使用结构体和指针来实现线性表的基本操作。下面是一些常见的线性表操作：

1. 初始化线性表

typedef struct ListNode{
    int data;
    struct ListNode *next;
} ListNode;

typedef struct {
    ListNode *head;
    int length;
} List;

void initList(List *list){
    list->head = NULL;
    list->length = 0;
}

2. 插入元素

void insert(List *list, int index, int data){
    if(index < 0 || index > list->length){
        printf("Error: index out of range\n");
        return;
    }
    ListNode *node = (ListNode*)malloc(sizeof(ListNode));
    node->data = data;
    if(index == 0){
        node->next = list->head;
        list->head = node;
    }else{
        ListNode *prev = list->head;
        for(int i=0; i<index-1; i++){
            prev = prev->next;
        }
        node->next = prev->next;
        prev->next = node;
    }
    list->length++;
}

3. 删除元素

void delete(List *list, int index){
    if(index < 0 || index >= list->length){
        printf("Error: index out of range\n");
        return;
    }
    if(index == 0){
        ListNode *temp = list->head;
        list->head = temp->next;
        free(temp);
    }else{
        ListNode *prev = list->head;
        for(int i=0; i<index-1; i++){
            prev = prev->next;
        }
        ListNode *temp = prev->next;
        prev->next = temp->next;
        free(temp);
    }
    list->length--;
}

4. 查找元素

int search(List *list, int data){
    ListNode *node = list->head;
    int index = 0;
    while(node != NULL){
        if(node->data == data){
            return index;
        }
        node = node->next;
        index++;
    }
    return -1;
}

5. 修改元素

void update(List *list, int index, int data){
    if(index < 0 || index >= list->length){
        printf("Error: index out of range\n");
        return;
    }
    ListNode *node = list->head;
    for(int i=0; i<index; i++){
        node = node->next;
    }
    node->data = data;
}