Question

C语言链表尾插法为什么我只能插入后两个

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

typedef struct myStruct
{
int date;
struct myStruct *pNext;
}Snake;

Snake *add(Snake *pHead,int date)
{
Snake *pNew = (Snake*)malloc(sizeof(Snake)); //尾插法
Snake *pTile = pHead; //备份一下头节点
pNew->date = date;
pNew->pNext = NULL;
if(pHead == NULL)
{
pHead = pNew;
}
else
{
while(pTile->pNext)
{
pTile = pTile->pNext; //循环前进
}
pTile->pNext = pNew;
}
}
void show(Snake *p) //打印
{
if(p == NULL)
{
return ;
}else
{
printf("%d,%p,%p\n",p->date,p,p->pNext);
show(p->pNext);
}
}

int main()
{
Snake *pHead = NULL;
pHead = add(pHead,11);
pHead = add(pHead,12);
pHead = add(pHead,13);
pHead = add(pHead,14);
pHead = add(pHead,15);
show(pHead);
system("pause");
return 0;
}

Answer 1

//函数add()有返回值,在末尾要有return pHead;

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

typedef struct myStruct
{
    int date;
    struct myStruct *pNext;
}Snake;

Snake *add(Snake *pHead,int date)
{
    Snake *pNew = (Snake*)malloc(sizeof(Snake)); //尾插法
    Snake *pTile = pHead; //备份一下头节点
    pNew->date = date;
    pNew->pNext = NULL;
    if(pHead == NULL)
    {
        pHead = pNew;
    }
    else
    {
        while(pTile->pNext)
        {
            pTile = pTile->pNext; //循环前进
        }
        pTile->pNext = pNew;
    }

    return pHead; //增加这个返回语句
}
void show(Snake *p) //打印(递归法)
{
    if(p == NULL)
    {
        return ;
    }
    else
    {
        printf("%d,%p,%p\n",p->date,p,p->pNext);
        show(p->pNext);
    }
}

int main()
{
    Snake *pHead = NULL;
    pHead = add(pHead,11);
    pHead = add(pHead,12);
    pHead = add(pHead,13);
    pHead = add(pHead,14);
    pHead = add(pHead,15);
    show(pHead);
    system("pause");
    return 0;
}