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

typedef struct node
{
    int item;
    struct node* next;
} NODE;

NODE *insert(NODE *head, int num);
NODE *search(NODE *head, int num);
void destroy(NODE *head);
int main()
{
    NODE *head = NULL, *p;
    int num;
    while(scanf("%d", &num)!=EOF) {
        head = insert(head, num);
    }

    for(p=head;p!=NULL;p=p->next) {
        printf("%d ", p->item);
    }
    printf("\n");

    int count=0;
    for(p=head;p!=NULL;p=p->next) {
        if((p=search(p, 100))!=NULL) count++;
        else break;
    }
    printf("num of 100 is %d.\n", count);

    destroy(head);
}

NODE *insert(NODE *head, int num)
{
    NODE *p = malloc(sizeof(NODE));
    if(p == NULL) {printf("error!\n");exit(1);}
    p->item = num;
    p->next = head;
    return p;
}

NODE *search(NODE *head, int num)
{
    NODE *p;
    for(p=head;p!=NULL;p=p->next) {
        if(p->item == num) break;
    }
    return p;
}

void destroy(NODE *head)
{
    NODE *p,*q;
    for(p=head;p!=NULL;p=q) {
        q=p->next;
        free(p);
    }
}

在这个程序中作进一步改进
要求实现函数delete从链表中摘除用search找到的节点，最后调用free释放它的存储空间

前面写了那么多了，自己接着写呗