单链表

说到链表，从大一就开始折腾，不复杂的一个东西愣是到现在也没好好实现过。说到底是自己执行力太低了。准备考研也有一段时间了，数据结构看了也有一段时间，该写点代码了。

链表没什么好说的，概念和方法都很简单，就直接贴代码吧，下面的实现是带头结点的。想了下，C++自己太半桶水了，还是老实用C吧，等初试完了再好好看看C++.

LinkList.h

#ifndef LINKLIST_H_INCLUDED
#define LINKLIST_H_INCLUDED

typedef int ElemType;

struct Node;
typedef struct Node* PtrToNode;
typedef PtrToNode LinkList;
typedef PtrToNode Position;

LinkList L_creatList();
void L_destroyList(LinkList list);
void L_makeEmpty(LinkList list);
void L_insert(Position pos, ElemType elem);
void L_delete(LinkList list, ElemType elem);
Position L_find(LinkList list, ElemType elem);
/* Locate the previous node for delete method */
Position L_findPre(LinkList list, ElemType elem);
int L_isEmpty(LinkList list);
/* routine for test */
void L_printList(LinkList);  
//PtrToNode L_header(LinkList list);


#endif // LINKLIST_H_INCLUDED

implementation is in the source file LinkList.c

#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include "LinkList.h"

typedef struct Node
{
    ElemType data;
    PtrToNode next;
}Node;

LinkList L_creatList()
{
    LinkList L;

    L = malloc(sizeof(Node));
    /* Check the alloction */
    assert(L != NULL);
    L->next = NULL;

    return L;
}

Position L_find(LinkList list, ElemType elem)
{
    Position p = list->next;

    while(p != NULL){
        if(p->data == elem)
            return p;
        p = p->next;
    }

    /* Not found */
    return NULL;
}

Position L_findPre(LinkList list, ElemType elem)
{
    Position pre = list;
    Position cur = pre->next;

    while(cur != NULL){
        if(cur->data == elem)
            return pre;
        pre = pre->next;
        cur = pre->next;
    }

    return NULL;
}

/* Insert the Node after the position */
void L_insert(Position pos, ElemType elem)
{
    Position tmp = malloc(sizeof(Node));
    assert(tmp != NULL);
    tmp->data = elem;
    tmp->next = NULL;

    tmp->next = pos->next;
    pos->next = tmp;
}

int L_isEmpty(LinkList list)
{
    return list->next == NULL;
}

void L_delete(LinkList list, ElemType elem)
{
    Position pre = L_findPre(list, elem);

    if(pre != NULL){
        Position tmp = pre->next;
        pre->next = tmp->next;
        free(tmp);
    }
}

void L_makeEmpty(LinkList list)
{
    LinkList L = list;
    Position tmp;

    while(L->next != NULL){
        tmp = L->next;
        L->next = tmp->next;
        free(tmp);
    }
}

void L_destroyList(LinkList list)
{
    L_makeEmpty(list);
    free(list);
}

/* This routine just for test */
void L_printList(LinkList list)
{
    LinkList L = list->next;

    while(L != NULL){
        printf("%d ", L->data);
        L = L->next;
    }

    printf("\n");
}

之后几天把基本的数据结构补齐，就可以写写基本的算法了，包括之前写的排序，准备再用C实现下。