Problem:
Binary Search Tree III

Write a program which performs the following operations to a binary search tree $T$ by adding delete operation to B: Binary Search Tree II.

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

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

delete $k$: Delete a node containing $k$.

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

The operation delete $k$ for deleting a given node $z$ containing key $k$ from $T$ can be implemented by an algorithm which considers the following cases:

If $z$ has no children, we modify its parent $z.p$ to replace $z$ with NIL as its child (delete $z$).

If $z$ has only a single child, we "splice out" $z$ by making a new link between its child and its parent.

If $z$ has two children, we splice out $z$'s successor $y$ and replace $z$'s key with $y$'s key.

Input

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

18
insert 8
insert 2
insert 3
insert 7
insert 22
insert 1
find 1
find 2
find 3
find 4
find 5
find 6
find 7
find 8
print
delete 3
delete 7
print

Sample Output 1

yes
yes
yes
no
no
no
yes
yes
1 2 3 7 8 22
8 2 1 3 7 22
1 2 8 22
8 2 1 22

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)

/*s1190073  Rina Sato
  File name: prog8a.c
  This is a binary search tree program.
*/

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

struct node{
  struct node *right;
  struct node *left;
  struct node *parent;
  int key;
};
typedef struct node * Node;

#define NIL NULL

Node root;

Node treeMinimum(Node x){
  while(x->left != NIL){
    x = x->left;
  }
  return x;
}

Node treeSearch(Node u, int k){
  while((u != NIL) && (k != u->key)){
    if(k < u->key){
      u = u->left;
    }
    else {
      u = u->right;
    }
  }
  
  return u;
}

Node treeSuccessor(Node x){
  Node y;

  if(x->right != NIL){
    return treeMinimum(x->right);
  }
  y = x->parent;
  
  while((y != NIL) && (x == y->right)){
    x = y;
    y = y->parent;
  }

  return y;
}

void treeDelete(Node z){
  Node y; // node to be deleted
  Node x; // child of y

  if((z->left == NIL) || (z->right == NIL)){
    y = z;
  }
  else {
    y = treeSuccessor(z);
  }

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

  if(x != NIL){
    x->parent = y->parent;
  }
  if(y->parent == NIL){
    root = x;
  }
  else if(y == y->parent->left){
    y->parent->left = x;
  }
  else {
    y->parent->right = x;
  }

  if(y != z){
    z->key = y->key;
  }
}

void Insert(int k){
  Node y = NIL;
  Node x = root;
  Node z;

  z = 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(Node u){
  if(u->left != NIL){
    Inorder(u->left);
  }
  printf(" %d",u->key);
  
  if(u->right != NIL){
    Inorder(u->right);
  }
}

void Preorder(Node u){
  printf(" %d",u->key);
  if(u->left != NIL){
    Preorder(u->left);
  }
  if(u->right != NIL){
    Preorder(u->right);
  }
}

int main(){
  int n, i, x;
  char com[20];;
  Node t;

  scanf("%d", &n);

  root = malloc(sizeof(struct node));
  root = NIL;
  
  for ( i = 0; i < n; i++ ){
    scanf("%s", com);
    if ( com[0] == 'f' ){ /*if I find 'x',print yes.else print no.*/
      scanf("%d", &x);
      t = treeSearch(root, x);
      if (t != NIL) printf("yes\n");
      else printf("no\n");
    } else if (com[0] == 'i'){
      scanf("%d", &x);
      Insert(x);
    } else if (com[0] == 'p'){ /*print inorder tree walk and preorder tree walk*/
      Inorder(root);
      printf("\n");
      Preorder(root);
      printf("\n");
    } else if (com[0] == 'd'){ /*delete 'x'*/
      scanf("%d", &x);
      treeDelete(treeSearch(root,x));
    }
  }

  return 0;
}