Problem:
Binary Search Tree II

Write a program which performs the following operations to a binary search tree $T$ by adding the find operation to A: Binary Search Tree I.

insert $k$: Insert a node containing $k$ as key into $T$.

find $k$: Report whether $T$ has a node containing $k$.

print: Print the keys of the binary search tree by inorder tree walk and preorder tree walk respectively.

Input

In the first line, the number of operations $m$ is given. In the following $m$ lines, operations represented by insert $k$, find $k$ or print are given.

Output

For each find $k$ operation, print "yes" if $T$ has a node containing $k$, "no" if not.

In addition, for each print operation, print a list of keys obtained by inorder tree walk and preorder tree walk in a line respectively. Put a space character before each key.

Constraints

The number of operations $\leq 500,000$

The number of print operations $\leq 10$.

$-2,000,000,000 \leq key \leq 2,000,000,000$

The height of the binary tree does not exceed 100 if you employ the above pseudo code.

The keys in the binary search tree are all different.

Sample Input 1

10
insert 30
insert 88
insert 12
insert 1
insert 20
find 12
insert 17
insert 25
find 16
print

Sample Output 1

yes
no
1 12 17 20 25 30 88
30 12 1 20 17 25 88

Reference

Introduction to Algorithms, Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford Stein. The MIT Press.

Solution in C (judge verdict: Accepted)

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

struct node{
  int key;
  struct node *right, *left, *parent;
};

struct node *root, *NIL;

struct node *find(struct node *,int);
void insert(int);
void inorder(struct node *);
void preorder(struct node *);

int main() {
  int n, i, x;
  char s[20];

  scanf("%d",&n);

  for(i=0;i<n;i++){
    scanf("%s%d",s,&x);
    if(s[0]=='i') insert(x);
    else if(s[0]=='f'){
      struct node *t = find(root, x);
      if(t!=NIL) printf("yes\n");
      else printf("no\n");
    }
    else{
      inorder(root);
      printf("\n");
      preorder(root);
      printf("\n");
    }
  }

  return 0;
}

void insert(int k){
  struct node *y = NIL;
  struct node *x = root;
  struct node *z;

  z = (struct node *)malloc(sizeof(struct node));
  z->key = k;
  z->left = NIL;
  z->right = NIL;

  while(x!=NIL){
    y = x;
    if(z->key < x->key) x = x->left;
    else x = x->right;
  }

  z->parent = y;
  if(y==NIL) root = z;
  else{
    if(z->key < y->key) y->left = z;
    else y->right = z;
  }
}

void inorder(struct node *u){
  if(u==NIL) return;
  inorder(u->left);
  printf(" %d",u->key);
  inorder(u->right);
}

void preorder(struct node *u){
  if(u==NIL) return;
  printf(" %d",u->key);
  preorder(u->left);
  preorder(u->right);
}

struct node *find(struct node *u, int k){
  while(u!=NIL && k!=u->key){
    if(k<u->key) u = u->left;
    else u = u->right;
  }
  return u;
}