THIS IS MY CODE

#include<stdio.h>
#include<stdlib.h>
typedef struct node
{
  int val;
  struct node *l,*r;
}NODE;

void entree(NODE* p,int a)
{
  if(a<p->val)
  {
    if(p->l==NULL)
    {
      p->l=(NODE*)malloc(sizeof(NODE));
      p=p->l;
      p->val=a;
      p->l=p->r=NULL;
    }
    else
      entree(p->l,a);
  }
  else
  {
    if(p->r==NULL)
    {
      p->r=(NODE*)malloc(sizeof(NODE));
      p=p->r;
      p->val=a;
      p->l=p->r=NULL;
    }
    else
      entree(p->r,a);
  }
}
void order(NODE *p)
{
   if(p->r!=NULL) order(p->r);
   if(p->l!=NULL) order(p->l);
   printf("%d ",p->val);
}

void main()
{
  NODE *first,*cur;
  int *ar,n;
  scanf("%d",&n);
  ar=(int *)malloc(sizeof(int)*n);
  for(int i=n-1;i>=0;i--)
    scanf("%d",ar+i);
  first=(NODE*)malloc(sizeof(NODE));
  first->val=*ar;
  first->l=first->r=NULL;
  for(i=1;i<n;i++)
  {
    cur=first;
    entree(cur,*(ar+i));
  }
  cur=first;
  order(cur);
}

ThAnKs FoR AdVaNcE

Declare your i variable in the main function along with the other ints (*ar, n), not in the for, and you'll get AC. I don't know why this happens cause in my Visual C++ it works like that... Also you cand take a look at the errors by choosing send result to mail, as I've done with your source now...

Thank YOUUU!! Very much ^o^

I think the problem was in the second loop "for": variable "i" was not declared...
//----------------------------
  for(i=1;i<n;i++)
  {
    cur=first;
    entree(cur,*(ar+i));
  }
//----------------------------