langc_algo_silgle_list.c

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

typedef struct sListElemt_{
	int data;
	struct sListElemt_ *next ;
}sListElemt;

typedef struct sList_{
	int size;
	sListElemt *pHead;
	sListElemt *pTail;
}sList;


sList list;



int initList(sList *pList)
{
	pList->size  = 0;
	pList->pHead = NULL;
	pList->pTail = NULL;
}

int addLisTToTail(sList *pSList,int  data)
{	
	sListElemt * pNewsListElemt;
	
	if((pNewsListElemt = (sListElemt *)  malloc(sizeof(sListElemt))) == NULL)
		return -1;
	
	pNewsListElemt->data = data;
	pNewsListElemt->next = NULL;
	
	if(pSList->size ==0){
		
		pSList->pHead= pNewsListElemt;
		pSList->pTail= pNewsListElemt;
	
	}else {
		
		pSList->pTail->next = pNewsListElemt;
		pSList->pTail = pNewsListElemt;	
	}	
		
	pSList->size++;
	
	return 0;	
}

int addListToHead(sList *pSList, int data)
{
	sListElemt * pNewsListElemt;
	
	if((pNewsListElemt = (sListElemt *)  malloc(sizeof(sListElemt))) == NULL)
		return -1;
	
	pNewsListElemt->data = data;
	pNewsListElemt->next = NULL;	
	
	if(pSList->size ==0){
		
		pSList->pHead= pNewsListElemt;
		pSList->pTail= pNewsListElemt;
	
	}else {
		
		pNewsListElemt->next = pSList->pHead; 
		pSList->pHead = pNewsListElemt;	
		
	}
	
	pSList->size++;
	
	return 0;
}


int getListToTail(sList *pSList, int *data)
{
	sListElemt * pListElemt;
		
	if(pSList->size < 1)
		return -1;
		
	if(pSList->size == 1){
		
		*data = pSList->pTail->data;
		
		free(pSList->pTail);
		pSList->pHead = NULL;
		pSList->pTail = NULL;
		
	}else{
		
		pListElemt = pSList->pHead;
		
		while(pListElemt->next != pSList->pTail)
			pListElemt = pListElemt->next;
		
		*data = pSList->pTail->data;
		free(pSList->pTail);
		pSList->pTail = pListElemt;
		
	}

	pSList->size--;
	
	return 0;
}



int getListToHead(sList *pSList, int *data)
{
	sListElemt * pListElemt;
		
	if(pSList->size < 1)
		return -1;
		
	if(pSList->size == 1){
		
		*data = pSList->pHead->data;
		free(pSList->pTail);
		pSList->pHead = NULL;
		pSList->pTail = NULL;
		
	}else{
		
		*data = pSList->pHead->data;
		pListElemt = pSList->pHead->next;
		free(pSList->pHead);
		pSList->pHead = pListElemt;
	}

	pSList->size--;
	
	return 0;
}

int displayListfromHead(sList *pSList)
{
	sListElemt * pListElemt;
	
	if(pSList->size < 1)
			return -1;
	
	pListElemt = pSList->pHead;
	
	printf("display len %d \n",pSList->size );
	

	do{
	
		printf("%d->",pListElemt->data);
		pListElemt = pListElemt->next;
		
	}while(pListElemt != NULL);
	
	printf("\n");
	
	return 0;
	
}



int main(void) {
     
     int i,data;
     
     initList(&list);
     
     for(i=0;i<10;i++)
     	addLisTToTail(&list,i+1);
     
     displayListfromHead(&list);
     
     for(i=0;i<10;i++)
     {
     //	getListToHead(&list,&data);
     	getListToTail(&list,&data);
     	printf("%d->",data);
     	
     }
     
	return 0;
}