?
Solved

count the height of a tree

Posted on 2000-04-15
1
Medium Priority
?
218 Views
Last Modified: 2010-04-16
I have a function that count the height of a tree

function countheight(root:tree):integer;
var left, right:integer;
begin
  if root=nil then countheight:=0
  else
     begin
   left:=countheight(root^.left);
   right:=countheight(root^.right);
   if left>right then countheight:=1+left
    else countheight:=1+right
   end;
end;

I don't know the IF condition so it can calculate the height of a tree
 
Please explain in details
0
Comment
Question by:adrianmak
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 2

Accepted Solution

by:
yairy earned 60 total points
ID: 2720464
this is a recursive function.

It says that the the hight of the tree is the hight of the left sub-tree+1 (if the left sub-tree is higher then the right sub-tree)
OR
the hight of the tree is the hight of the right sub-tree+1
(if the right  sub-tree is higher the the left one)

Now, how do we know  what sub-tree is higher ?

we will RECURSEVLY treat each sub-tree as a tree.

example:

            8
       3       11
                    30

hight(8)=max(hight(3),hight(11))+1
hight(3)=max(hight(NULL), hight(NULL))+1
hight(NULL)=0  // ending condition
==> hight(3)=0+1=1.

hight(11)=max(hight(NULL), hight(30))+1
hight(NULL)=0
hight(30)=max(hight(NULL), hight(NULL))+1
hight(NULL)=0
==> hight(30)=0+1=1
==> hight(11)=1+1=2
==> hight(8)=2+1 = 3

as you can see, the recursion goes 'backwards'
with the result back to the first call...

Any questions,
Yair




0

Featured Post

New feature and membership benefit!

New feature! Upgrade and increase expert visibility of your issues with Priority Questions.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

On September 18, Experts Exchange launched the first installment of the Help Bell, a new feature for Premium Members, Team Accounts, and Qualified Experts. The Help Bell will serve as an additional tool to help teams increase question visibility.
What we learned in Webroot's webinar on multi-vector protection.
Monitoring a network: how to monitor network services and why? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the philosophy behind service monitoring and why a handshake validation is critical in network monitoring. Software utilized …
Add bar graphs to Access queries using Unicode block characters. Graphs appear on every record in the color you want. Give life to numbers. Hopes this gives you ideas on visualizing your data in new ways ~ Create a calculated field in a query: …

719 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question