I got compile error when choose C, but get wrong answer if chosse C++. what's the problem.

#include <stdio.h>
#include <stdlib.h>
#define null 0

typedef struct Link{
        int data;
        struct Link *next;
        }Link, *LinkList;
#define L sizeof(struct Link)

Link * Create(int n)
{
    Link *p,*h,*s, *m;
    int i;
    int value;

    h = (Link *)malloc(L);
    h->data = 100001;
    h->next = null;

    for (i = 0; i < n; i++)
    {
        p = h;
        s = (Link *)malloc(L);
        scanf("%d",&value);
        s->data = value;

        while (p && p->data > s->data)
        {
            m = p;
            p = p->next;
        }

        m->next = s;
        s->next = p;
    }

    return (h);
}

int main(int argc, char *argv[])
{
    int number = 0;
    scanf("%d", &number);

  struct Link *header;
  header = Create(number);
  header = header->next;
  int min = 0;
  int max = 0;
  while (header)
  {
      if (min < max)
      {
          min += header->data;
      }
      else
      {
           max += header->data;
      }
      header = header->next;
  }

  printf("%d", min > max ? min - max : max - min);

  return 0;
}