数据结构 链表|简单链表

Description

链表是使用指针把一系列结点连接起来的数据结构。它由一系列结点（链表中每一个元素称为结点）组成，结点可以在运行时动态生成。每个结点包括两个部分：一个是存储数据元素的数据域，另一个是存储下一个结点地址的指针域。每个结点里的指针指向下一个结点，而链表的入口（head指针）指向第一个结点

现在请你实现一个简单的链表，具体请看头文件

Input

第一行是整数 n

接下来有n行，每行两个整数，代表插入的位置和插入的数据

Output

输入每次插入后的结果

Sample Input

30 11 2-1 3

Sample Output

11 2position is not valid

Hint

插入的position是以0计数的，比如当前是 1 2 3

• 如果输入0 4，则在0号位置插入4，变为 4 1 2 3
• 如果输入3 5，则在3号位置插入5，变为 1 2 3 5

• 如果输入不在 [0, size] 区间（size为当前个数），则位置不合法

main.c

#include <stdio.h>#include "linkedList.h"void print() {    int i;    for (i = 0; i < size; ++i) {        printf("%d ", get(i));    }    printf("\n");}int main() {    head = NULL;    size = 0;    int n, i, position, value;    scanf("%d", &n);    for (i = 0; i < n; i++) {        scanf("%d%d", &position, &value);        if (insert(position, value)) {            print();        } else {            printf("position is not valid\n");        }    }    clear();    return 0;}

linkedList.h

#ifndef LINKEDLIST_H#define LINKEDLIST_H#include <stdbool.h>typedef struct node {    int value;    struct node* next;} node ;int size; // the size of linked listnode* head; // the head of linkedlist//insert the value to the right position//if the position is not valid, return false//if insert successfully, return truebool insert(int position, int value);// return the value in the given positionint get(int position);//clear the linkedlist, remember to free the memory you allocatedvoid clear();#endif

linkedList.c

#include <stdio.h>#include <stdlib.h>#include <stdbool.h>typedef struct node {    int value;    struct node* next;} node ;int size; // the size of linked listnode* head; // the head of linkedlist//insert the value to the right position//if the position is not valid, return false//if insert successfully, return truebool insert(int position, int value);// return the value in the given positionint get(int position);//clear the linkedlist, remember to free the memory you allocatedvoid clear();bool insert(int position, int value){    if (position > size || position < 0)        return 0;    if (size == 0)    {        head = (node *)malloc(sizeof(node));        head -> value = value;        head -> next = NULL;        size ++;    }    else if (position == 0)    {        node * ph = (node*)malloc(sizeof(node));        ph -> value = value;        ph -> next = head;        head = ph;        size ++;    }    else    {        node * p = head;        node * q = NULL;        int i = 0;        for (i = 0; i < position - 1; ++ i)        {            p = p -> next;        }        node * ins = (node *)malloc(sizeof(node));        q = p -> next;        p -> next = ins;        ins -> next = q;        ins -> value = value;        size ++;    }    return 1;}int get(int position){    node * temp = head;    while (position --)    {        temp = temp -> next;    }    return temp -> value;}void clear(){    node * pHead = head;    node * pNext;    if (pHead != NULL)    {        while (pHead != NULL)        {            pNext = pHead -> next;            free(pHead);            pHead = pNext;        }    }}