'/' : illegal, left operand has type 'struct node *'是什么意思?

Question

#include <stdio.h>#include <stdlib.h>#include <time.h>#define NODE struct node#define HEAD struct headNODE{ int data; NODE *next;};HEAD{ int count; NODE *first; NODE *last; NODE *sum; NODE *max; NODE *min; NODE *avg;};void init(HEAD *head){ head->count = 0; head->first = NULL; head->last = NULL; head->sum = NULL;}void addNode(HEAD *head, int data){ HEAD *s; NODE *b; int min, n; int avg; s = (HEAD *) malloc (sizeof(HEAD)); b->data = n; if (data < min)  min = data; b->next = s->first; s->first = b; s->sum += b->data; s->count ++; s->avg = s->sum / s->count; }void appendNode(HEAD *head, int data){ HEAD *q; NODE *b; int max, n; int avg; q = (HEAD *) malloc (sizeof(HEAD)); b->data = n; b->next = NULL; if (data > max)  max = data; if (emptyList(head))  head->first = b; else  q->last->next = b; q->last = b; q->count ++; q->sum += b->data; q->avg = q->sum / q->count;}int emptyList(HEAD *head){ if (head->count==0)  return 1; else  return 0;}int listCount(HEAD *head){ return (head->count);}void printList(HEAD *head){ int i; NODE *prnNode; prnNode = head->first; for (i=1; i<=head->count; i++) {  printf("%d\n", prnNode->data);  prnNode = prnNode->next; }}void prnList(HEAD *head){ NODE *prnNode; prnNode = head->first; while (prnNode != NULL) {  printf("%d\n", prnNode->data);  prnNode = prnNode->next; }}void main(){ HEAD *q, *s; int i, n; q = (HEAD *) malloc (sizeof(HEAD)); s = (HEAD *) malloc (sizeof(HEAD)); init(q); init(s); srand(time(NULL)); for (i=1; i<20; i++) {  n = rand() % 201 + 100;  if(n % 2 == 0)   appendNode(q, n);  else   addNode(s, n); } printf("\n Queue: \n"); prnList(q); printf("\n Stack: \n"); prnList(s); printf("\n\n\t count \t max \t min \t avg \n"); printf("Queue:\t %d \t %d \t \t %.2f \n", q->count, q->max, q->avg); printf("Stack:\t %d \t %d \t \t %.2f \n", s->count, s->min, s->avg); printf("\n\n");}求帮忙看看怎么改错啊！谢谢你啦！

Answer 1

s->avg = s->sum / s->count; sum和avg是node类型不能使用/，应该是s->avg->data=s->sum->data/s->count;
 q->avg = q->sum / q->count;也是
 链表不是这样建立的，imooc有视频