函数find_middle()实现了对给定的单链表，查找到其中间结点。如果中间结点为两个，返回前面的那个结点的地址

Question

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

typedef struct ListNode {
int num;
struct ListNode *next;
}Node;

Node createlist(); /裁判实现，细节不表/
Node find_middle(Node* head);
void display(Node *head);/裁判实现，细节不表/

int main()
{
Node *head,*p;
head = createlist();
p = find_middle(head);
display(p);
return 0;
}

Answer 1

Node* find_middle(Node* head)
{
     int count = 0;
     Node *p = head;
      if(p == NULL)
          return p;
      while(p->next != NULL)
      {
          count++;
          p = p->next;
      }
      p = head;
      count = count/2;
      while(count > 0)
      {
            p = p->next;
            count--;
      }
      return p;
}