谁能帮忙看看这链表。。。在删除链表总出问题

#include<stdio.h>
#include<stdlib.h>
#define LEN sizeof(struct work)

struct work{
    int num;
    char name[15];
    double gongzi;
    struct work *next;
};

int n;

struct work *create()//创建链表 
{
    struct work *head,*p1,*p2;
    n=0;
    p1 = p2 = (struct work *)malloc(LEN);
    scanf("%d %lf %s ",&p1->num,&p1->gongzi,p1->name);
    head = NULL;
    while(p1->num != 0)
    {
        n++;
        if(n == 1)   head = p1;
        else p2->next = p1;
        p2 = p1;
        p1 = (struct work *)malloc(LEN);
        scanf("%d%lf%s",&p1->num,&p1->gongzi,p1->name);
    }
    p2->next = NULL;
    return head;
}



struct work *del(struct work *head,int num)//删除链表的一行 
{
    struct work  *p1,*p2;
    if(head == NULL)
    {
        printf("此链表无,请确认链表有无创建");
        return head;
    }
    p1 = head;
    if(num != p1->num&&p1->next != NULL)
    {
        p2 = p1;
        p1 = p1->next;
    }
    if(p1->num == num)
    {
        if(head == p1)    head = p1->next;
        else p2->next = p1->next;
        printf("此数%d存在",num);
        free(p1);
        n--;
    }
    else printf("此数%d不存在",num);
    return head;
}

void print(struct work *head)
{
    struct work *p;
    p = head;
    while(p!=NULL)
    {
        printf("%d\t%s\t%.2lf\n",p->num,p->name,p->gongzi);
        p = p->next;
    }
}

void main()
{
    struct work *head;
    char pd;
    int num;
    head = create();
    print(head);
    printf("确认是否删除此表的一行??输入y为修改，否则不修改...请输入\n");
    scanf("%c",&pd);
    if(pd == 'y'||pd == 'Y')
        print(head);
    else
    {
        printf("请把不要行的开头数输入\n");
        scanf("%d",num);
        head = del(head,num);
        print(head);
    }
}

可以讲下为什么这么修改吗？？？我运行了，虽然可以，但我不太了解，能讲下吗？？

问下不清缓冲区的话，是不是scanf（"%c",&pd）;无法运行？？
初学者弱弱问句缓冲区什么概念？？要是介绍不清的话或打字有点多的话，能告诉下怎么查到这个解释。。

这是我失误，应该是while不是if