单向链表

#ifndef LINK_H
#define LINK_H

#define LEN sizeof(Link)
struct Node;
typedef struct Node * Link;
typedef int Type;
struct Node{
    Type E;
    Link Next;
};

Link MakeNode(Type E);
void Lpush(Link L);
void RPush(Link L);
void Insert();
Link Pop();
void MakeEmpty();
Link Search();
void PrintLink();

#endif

#include <stdio.h>
#include <stdlib.h>
#include "link.h"

static Link Head = NULL;

//生成节点
Link MakeNode(Type E){
    Link P = malloc(LEN);
    P->E = E;
    P->Next = NULL;
    return P;
}

//在链表左侧插入元素
void LPush(Link L){
    L->Next = Head;
    Head = L;
}

//在链表右侧插入元素
void RPush(Link L){
    if(Head == NULL){
        Head = L;
    }else{
        Link P = Head;
        while(P->Next != NULL){
            P = P->Next;
        }
        P->Next = L;
    }
}

//在指定元素位置后插入
void Insert(Link L ,Type E){        
    if(Head == NULL || Head->Next == NULL){//不足2个元素
        printf("InsertError:link length less than 2");
        return;
    }
    Link P = Search(E);
    if(P == NULL){//找不到指定元素
        printf("Insert Error:can't find element %d in link", E);
        return;
    }
    L->Next = P->Next;
    P->Next = L;
}

Link Pop(){
    if(Head == NULL){
        return NULL;
    }
    Link P = Head;
    Head = Head->Next;
    return P;
}

void MakeEmpty(){
    if(Head == NULL){
        return;
    }
    Link P, Tmp;
    P = Head;
    Head = NULL;
    while(P != NULL){
        Tmp = P;
        P = P->Next;
        free(Tmp);
    }
}

Link Search(Type E){
    Link P = Head;
    if(P == NULL){
        return NULL;
    }
    while(P != NULL){
        if(P->E == E){
            return P;
        }
        P = P->Next;
    }
    return NULL;
}

void PrintLink(){
    Link P = Head;
    if(P == NULL){
        printf("empty Link\n");
        return;
    }
    while(P != NULL){
        printf("%d ", P->E);
        P = P->Next;
    }
    printf("\n");
}


int main(int argc, char *argv[]){
    int i;
    Link P;
    for(i = 1; i <= 10; i++){
        P = MakeNode(i);
        RPush(P);
    }
    PrintLink();
    Pop();
    Pop();
    PrintLink();
    return 0;
}