13.1.22：带头结点的链表结构

/*
1.带头结点L的单链表结构
2.参照严慧敏单链表的链表结构

Levi
     date:13.1.22
*/

#include <stdio.h>
#include "sys/malloc.h"
#include <stdlib.h>
#define ElemType int


struct LNode{
    ElemType data;
    struct LNode * next;
};

typedef struct LNode * LinkList;

void InitList(LinkList *L){
    *L=(LinkList)malloc(sizeof(struct LNode));
    if(!(*L))
              printf("Failed to allocate memory for L !!!");
    (*L)->next=NULL;
}

void DestroyList(LinkList *L){
    LinkList p;
    while(*L){
        p=(*L)->next;
        free(*L);
        *L=p;
    }
}

void ClearList(LinkList L){
    LinkList p,q;
    p=L->next;
    while(p){
        q=p->next;
        free(p);
        p=q;
    }
    L->next=NULL;
}

void ListEmpty(LinkList L){
    if(L->next)
              printf("The LinkList is not NULL\n");
    else
              printf("The LinkList is NULL\n");
              
}

int ListLength(LinkList L){
    int i=1;
    LinkList q;
    q=L->next;
    while(q->next){
        q=q->next;
        ++i;
    }
    return i;
}

int GetElem(LinkList L,int i,ElemType *e){
    LinkList p;
    p=L->next;
    int count=1;
    while(p&&count<i){
        p=p->next;
        ++count;
    }
    if(!p||count>i){
              printf("The GetElem is failure !!!\n");
              return -1;
    }
    *e=p->data;
    return 0;
}

int LocateElem(LinkList L,ElemType x){
    LinkList p;
    p=L->next;
    int count=1;
    while(p->data!=x&&p){
        ++count;
        p=p->next;
    }
    if(!p){
              printf("The linkList have not the Element .\n");
              return -1;
    }
    return count;
}

int ListInsert(LinkList L,int i,ElemType e){
    LinkList p;
    p=L->next;
    LinkList s=(LinkList)malloc(sizeof(struct LNode));
    if(!s){
              printf("S error!\n");
              return -1;
    }
    if(i==1){
        s->data=e;
        s->next=p;
        L->next=s;
        return 0;
    }
    int count=1;
    while(p&&count<i-1){
        p=p->next;
        ++count;
    }
    if(!p||count>i-1){
        printf("Insert failure .\n");
        return -1;
    }
    s->data=e;
    s->next=p->next;
    p->next=s;
    return 0;
}

int ListDelete(LinkList L,int i,ElemType *e){
    LinkList p,q;
    p=L->next;
    int count=1;
//    if (i<1||i>ListLength(L)){
//        printf("i is error !\n");
//        return 0;
//    }
     if (i==1){
        L->next=p->next;
        *e=p->data;
        free(p);
        return 0;
    }
    while(p&&count<i-1){
        p=p->next;
        ++count;
    }
    if(!p||count>i-1){
        printf("Delete failure.\n");
        return 0;
    }
    q=p->next;
    *e=q->data;
    p->next=q->next;
    free(q);
    q=NULL;
    return 0;
}

void print(ElemType c){
    printf("%d ",c);
}

void print(ElemType c);
void ListTraverse(LinkList L,void(* vi)(ElemType)){
    LinkList p=L->next;
    while(p){
        vi(p->data);
        p=p->next;
    }
    printf("\n");
}



void CreateList(LinkList *L,int n){
    int i;
    LinkList p;
    *L=(LinkList)malloc(sizeof(struct LNode));
    (*L)->next=NULL;
    printf("Please input  Link_len = %d : \n",n);
    for(i=n;i>0;--i){
        p=(LinkList)malloc(sizeof(struct LNode));
        scanf("%d",&p->data);
        p->next=(*L)->next;
        (*L)->next=p;
    }
}

void CreateList1(LinkList *L,int n){
    int i;
    LinkList p,q;
    (*L)=(LinkList)malloc(sizeof(struct LNode));
    (*L)->next=NULL;
    q=(*L);
    printf("Please input  Link_len = %d : \n",n);
    for(i=n;i>0;--i){
        p=(LinkList)malloc(sizeof(struct LNode));
        scanf("%d",&p->data);
        q->next=p;
        q=q->next;
    }
    p->next=NULL;
}

void MergeList(LinkList La,LinkList Lb,LinkList *Lc){
    LinkList pa=La->next,pb=Lb->next,pc;
    *(Lc)=pc=La;
    while(pa&&pb){
        if(pa->data<=pb->data){
            pc->next=pa;
            pc=pa;
            pa=pa->next;
        }
        else{
            pc->next=pb;
            pc=pb;
            pb=pb->next;
        }
        pc->next=pa?pa:pb;
        free(Lb);
        Lb=NULL;
    }
}

int main(){
    LinkList La,Lb,Lc;
    
    InitList(&L);
    int j;
    for(j=1;j<=5;j++){
        ListInsert(L,1,j);
    }
    ListTraverse(L,print);
    ListEmpty(L);
    int e;
    ListDelete(L,41,&e);    
    ListTraverse(L,print);
    printf("%d\n",e);
    printf("********\n");
    printf("%d\n",ListLength(L));
    ListEmpty(L);

    printf("********\n");
    GetElem(L,4,&e);
    printf("%d\n",e);

    printf("********\n");
    int dis=LocateElem(L,2);
    printf("%d",dis);
    
    int n=5;
    CreateList1(&La,n);
    ListTraverse(La,print);
    CreateList1(&Lb,n);
    ListTraverse(Lb,print);
    MergeList(La,Lb,&Lc);
    ListTraverse(Lc,print);
    
    scanf("%*s");

    return 0;
}