C语言 数据结构 链表 基本操作代码

#include 
#include 
#define DataType int




typedef struct node {
    DataType data;
    struct node* next;
}LinkList;

void initList(LinkList *list) {
    if (list != NULL) {
        list = (LinkList*) malloc(sizeof(LinkList));
    }
}

void addHead(LinkList *list, int data) {
    if (list == NULL) {
        initList(list);
    }
    LinkList *p;
    p = (LinkList*) malloc(sizeof(LinkList));
    p -> data = data;
    p -> next = list -> next;
    list -> next = p;
}

LinkList* createLinkListByTail(int data[]) {
    int size = sizeof(data) / sizeof(int);
    LinkList *list;
    LinkList *tail, *temp;
    for(int i = 0;i < size;i ++) {
        int d = data[i];
        temp = (LinkList*) malloc(sizeof(LinkList));
        temp -> data = d;
        if(list == NULL) {
            list = temp;
            tail = temp;
        } else {
            tail -> next = temp;
            tail = temp;
        }
    }
    return list;
}

int getLength(LinkList* list) {
    int length = 0;
    LinkList *temp = list;
    while(temp != NULL) {
        length ++;
        temp = temp -> next;
    }
    return length;
}

DataType getDataByPos(LinkList *list, int pos) {
    LinkList *iterator = list;
    for(int i = 0;i < pos && iterator != NULL;i ++) {
        iterator = iterator -> next;
    }
    if(iterator != NULL) {
        return iterator -> data;
    } else {
        return NULL;
    }
}

DataType* getData(LinkList* list) {
    int length = getLength(list);
    DataType data[length];
    LinkList  *temp = list;
    int iterator = 0;
    while(temp != NULL) {
        data[iterator ++] = temp -> data;
        temp = temp -> next;
    }
    return data;
}


int insertData(LinkList* list, int pos, DataType data) {
    LinkList *iterator = list, *temp = (LinkList*) malloc(sizeof(LinkList));
    int insertFlag = 1;
    for(int i = 0;i < pos && iterator != NULL;i ++) {
        iterator = iterator -> next;
    }
    if(iterator != NULL) {
        temp->data = data;
        temp->next = iterator->next;
        iterator->next = temp;
    } else {
        insertFlag = 0;
    }
    
    return insertFlag;
}


int deleteData(LinkList* list, int pos) {
    LinkList *iterator = list;
    LinkList *pre_iterator;
    int deleteFlag = 0;
    for(int i = 0;i < pos && iterator != NULL;i ++) {
        pre_iterator = iterator;
        iterator = iterator -> next;
    }
    if(iterator != NULL) {
        deleteFlag = 1;
        pre_iterator -> next = iterator -> next;
        free(iterator);
    } else {
        deleteFlag = -1;
    }
    
    return deleteFlag;
}