线性表的链式存储实现（带头结点）

LinkedList.h

#ifndef LINKLIST_H_INCLUDE
#define LINKLIST_H_INCLUDE

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#define ERROR -1

typedef int ElementType;

typedef struct LNode* PtrToNode;
struct LNode{
    ElementType Data;
    PtrToNode Next;
};

typedef PtrToNode Position;        //这里的位置某个结点的结点指针
typedef PtrToNode List;


List MakeEmpty();


//链表长度
int Length(List L);

//根据位序查找元素
ElementType FindKth(List L, int K);

//根据元素查找相应的结点
Position Find(List L, ElementType X);

//在指定位置之后插入元素
List Insert(List L, ElementType X, int i);

bool Delete(List L, int i);

void printList(List L);




#endif

LinkedList.c

#include "LinkedList.h"

List MakeEmpty()
{
    List L = (List)malloc(sizeof(struct LNode));
    L->Next = NULL;
    L->Data = 0;
    return L;
}

int Length(List L)
{
    int cnt = 0;
    List p = L->Next;        //当前p指向第一个结点
    while (p)
    {
        cnt++;
        p = p->Next;

    }
    return cnt;

}

ElementType FindKth(List L, int K)
{
    Position p = L->Next;
    int cnt = 1;
    while (p && cnt < K)
    {
        p = p->Next;
        cnt++;
    }
    if ((cnt == K) && p)
        return p->Data;
    else
        return ERROR;
}

Position Find(List L, ElementType X)
{
    Position p = L -> Next;
    while (p && p->Data != X)
        p = p->Next;
    if (p)
        return p;
    else
        return NULL;
}

List Insert(List L, ElementType X, int i)
{
    Position tmp, pre;
    tmp = (Position)malloc(sizeof(struct LNode));

    int cnt = 0;
    pre = L;
    while (pre && cnt < i - 1)
    {
        pre = pre->Next;
        cnt++;
    }
    if (pre == NULL || cnt != i - 1)        //如果所招结点不再L中
    {
        printf("Insert position parameter error!
");
        free(tmp);
        return L;
    }
    else
    {
        tmp->Data = X;
        tmp->Next = pre->Next;
        pre->Next = tmp;
        return L;
    }

}

bool Delete(List L, int i)
{
    Position tmp, pre;
    int cnt = 0;
    pre = L;


    while (pre && cnt < i - 1)
    {
        pre = pre->Next;
        cnt++;
    }
    if (pre == NULL || cnt != i - 1 || pre->Next == NULL)        //i出错或链表为空
    {
        printf("Delete position parameter error!
");
        return false;
    }
    else
    {
        tmp = pre->Next;
        pre->Next = tmp->Next;
        free(tmp);
        return true;
    }


}

void printList(List L)
{
    Position p;
    p = L -> Next;
    while (p)
    {
        printf("%d ", p->Data);
        p = p->Next;
    }
    printf("
");
    return;
}