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

typedef struct _treenode {
   int id;
   struct _treenode *L;
   struct _treenode *R;
} treenode;

typedef treenode *tree;

tree treecons ( int i, int j )
{
   tree T;

   if (i > j) return NULL;

   T = (tree)malloc(sizeof(treenode));

   if (i == j) { T -> id = i;  T -> L = T -> R = NULL; return T; }

   T -> id = i + rand() % (j - i + 1);

   T -> L = treecons(i, (T->id)-1);
   T -> R = treecons((T->id)+1, j);

   return T;
}

void printtree ( tree T )
{
   if (T == NULL) return;
   printtree(T -> L);
   printf("%d %d %d\n",
            T -> id,
            (T -> L == NULL) ? -1 : T -> L -> id,
            (T -> R == NULL) ? -1 : T -> R -> id
         );
   printtree(T -> R);
}

int main ( int argc, char *argv[] )
{
   int i, rollno, n;
   tree T;

   if (argc != 2) {
      fprintf(stderr, "Compile treecons.c, and run with your roll number.\n");
      fprintf(stderr, "\t$ gcc -o treecons treecons.c\n");
      fprintf(stderr, "\t$ ./treecons 99FB1331 > tree.dat\n");
      fprintf(stderr, "Run your program like this:\n");
      fprintf(stderr, "\t$ ./a.out < tree.dat\n");
      exit(1);
   }
   for (i=0; i<strlen(argv[1]); ++i) {
      if ((argv[1][i] < '0') || (argv[1][i] > '9')) argv[1][i] = '0' + (argv[1][i] % 10);
   }
   rollno = atoi(argv[1]);
   fprintf(stderr, "Roll number converted to %d\n", rollno);
   srand((unsigned int)rollno);
   n = 1000 - (rand() % 100);
   T = treecons(0,n-1);
   printf("%d\n", n);
   printtree(T);
   exit(0);
}