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)

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

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

void insert(int);
struct Node *find(struct Node *,int);
struct Node *treeMinimum(struct Node *x);
struct Node *treeSuccessor(struct Node *x);
void treeDelete(struct Node *z);
void inorder(struct Node *);
void preorder(struct Node *u);

struct Node *root,*NIL;

int main(){
  int m,i,k;
  char com[20];

  scanf("%d",&m);

  for(i=0;i<m;i++){
  scanf("%s",com);
 
    if(com[0]=='i'){
        scanf("%d",&k);
        insert(k);
    }
    else if(com[0]=='f'){
        scanf("%d",&k);

        struct Node *u=find(root,k);
    
        if(u==NIL) printf("no\n");
        else printf("yes\n");
    }
    else if (com[0]=='p'){
        inorder(root);
        printf("\n");
        preorder(root);
        printf("\n");
    }
    else if(com[0]=='d'){
        scanf("%d",&k);

        treeDelete(find(root,k));
    }
  }

  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;
  }
}

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;
}

struct Node *treeMinimum(struct Node *x){
    while(x->left!=NIL) x=x->left;

    return x;
}

struct Node *treeSuccessor(struct Node *x){
    if(x->right!=NIL) return treeMinimum(x->right);

    struct Node *y=x->parent;

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

    return y;
}

void treeDelete(struct Node *z){
    struct Node *y;
    struct Node *x;

    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;

    free(y);
}

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);
}