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The binary tree structure can be used as an efficient way to organize data objects that are totally ordered. This is done by maintaining the tree in such a way that for any given subtree, the data elements in its left subtree are less than the root and the data elements in the right subtree are greater than the root. Such a binary tree is called a binary search tree.

Binary search tree

1. binary search tree property (bstp)

Consider the following binary tree of Integer objects.

-7 |_ -55| |_ [] | |_ -16| |_ -20 | | |_ []| | |_ [] | |_ -9| |_ [] | |_ []|_ 0 |_ -4| |_ [] | |_ []|_ 23 |_ []|_ []

Notice the following property:

  • all elements in the left subtree are less than the root element,
  • and the root element is less than all elements in the right subtree.

Moreover, this property holds recursively for all subtrees.  It is called the binary search tree (BST) property.  

In general, instead of Integer objects, suppose we have a set of objects that can be compared for equality with "equal to" and "totally ordered" with an order relation called "less or equal to" .  Define "less than" to mean "less or equal to" AND "not equal to".  Let T be a BiTree structure that stores such totally ordered objects.  

Definition of binary search tree property

The binary search tree property (BSTP) is defined on the binary tree structure as follows.

  • An empty binary tree satisfies the BSTP.
  • A non-empty binary tree T satisfies the BSTP if and only if 
    • the left and right subtrees of T both satisfy BSTP, and 
    • all elements in the left subtree of T are less than the root of T, and 
    • the root of T is less than all elements in the right subtree of T.

We can take advantage of this property when looking up for a particular ordered object in the tree.  Instead of scanning the whole tree for the search target, we can compare the search target against the root element and narrow the search to the left subtree or the right subtree if necessary.  So in the worst possible case, the number of comparisons is proportional to the height of the binary tree.  This is a big win if the tree is balanced .  It can be proven that when a tree containing N elements is balanced, its height is at most a constant multiple of logN.  For example, the height of a balanced tree containing 10 6 elements is at most a fixed multiple of 6.  Here is the definition of what a balanced tree is.

Definition of balanced tree

  • An empty tree is balanced .
  • A non-empty tree is balanced if and only if
    •  its subtrees are balanced and
    • the heights of the subtrees differ by a fixed constant or by a fixed constant factor.

A binary tree with  the BST property is called a binary search tree.  It can serve as an efficient way for storage/retrieval of data.  We are lead to the following question: how to create and maintain a binary search tree?  

2. binary search tree insertion

Suppose we start with an empty binary tree T and  a  Comparator that models a total ordering in a given set of objects S.  Then T clearly has the BST property with respect the Comparator ordering of S.  The following algorithm (visitor on binary trees) will allow us to insert elements of S into T and at the same time maintain the BST property for T.  This algorithm also works for binary search tree containing Comparable objects.

Questions & Answers

what is math number
Tric Reply
x-2y+3z=-3 2x-y+z=7 -x+3y-z=6
Sidiki Reply
Need help solving this problem (2/7)^-2
Simone Reply
x+2y-z=7
Sidiki
what is the coefficient of -4×
Mehri Reply
-1
Shedrak
the operation * is x * y =x + y/ 1+(x × y) show if the operation is commutative if x × y is not equal to -1
Alfred Reply
An investment account was opened with an initial deposit of $9,600 and earns 7.4% interest, compounded continuously. How much will the account be worth after 15 years?
Kala Reply
lim x to infinity e^1-e^-1/log(1+x)
given eccentricity and a point find the equiation
Moses Reply
12, 17, 22.... 25th term
Alexandra Reply
12, 17, 22.... 25th term
Akash
College algebra is really hard?
Shirleen Reply
Absolutely, for me. My problems with math started in First grade...involving a nun Sister Anastasia, bad vision, talking & getting expelled from Catholic school. When it comes to math I just can't focus and all I can hear is our family silverware banging and clanging on the pink Formica table.
Carole
I'm 13 and I understand it great
AJ
I am 1 year old but I can do it! 1+1=2 proof very hard for me though.
Atone
hi
Adu
Not really they are just easy concepts which can be understood if you have great basics. I am 14 I understood them easily.
Vedant
find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
salma
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
If f(x) = x-2 then, f(3) when 5f(x+1) 5((3-2)+1) 5(1+1) 5(2) 10
Augustine
how do they get the third part x = (32)5/4
kinnecy Reply
make 5/4 into a mixed number, make that a decimal, and then multiply 32 by the decimal 5/4 turns out to be
AJ
how
Sheref
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
I rally confuse this number And equations too I need exactly help
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But this is not salma it's Faiza live in lousvile Ky I garbage this so I am going collage with JCTC that the of the collage thank you my friends
salma
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
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Tamia
hii
Uday
hi
salma
hi
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Hello
opoku
hi
Ali
greetings from Iran
Ali
salut. from Algeria
Bach
hi
Nharnhar
A soccer field is a rectangle 130 meters wide and 110 meters long. The coach asks players to run from one corner to the other corner diagonally across. What is that distance, to the nearest tenths place.
Kimberly Reply
Jeannette has $5 and $10 bills in her wallet. The number of fives is three more than six times the number of tens. Let t represent the number of tens. Write an expression for the number of fives.
August Reply
What is the expressiin for seven less than four times the number of nickels
Leonardo Reply
How do i figure this problem out.
how do you translate this in Algebraic Expressions
linda Reply
why surface tension is zero at critical temperature
Shanjida
I think if critical temperature denote high temperature then a liquid stats boils that time the water stats to evaporate so some moles of h2o to up and due to high temp the bonding break they have low density so it can be a reason
s.
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
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Source:  OpenStax, Principles of object-oriented programming. OpenStax CNX. May 10, 2013 Download for free at http://legacy.cnx.org/content/col10213/1.37
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