1. Presented By: Mahmoud Rafeek Alfarra
MINISTRY OF EDUCATION & HIGHER EDUCATION
COLLEGE OF SCIENCE AND TECHNOLOGY
KHANYOUNIS- PALESTINE
Data structure
Using C#
Information Technology , 3’rd Semester
Lecture 16:
Trees Operations (Removing nodes)
Presented By: Mahmoud Rafeek Alfarra

2. Outline Deleting a Node With One Child
Deleting a Node With Two Children
Emank X Mezank !!

3. Deleting a Node With One Child
When the node to be deleted has one child, there are four conditions we have to check for:
The node’s child can be a left child; or
The node’s child can be a right child; or
The node to be deleted can be a left child; or
The node to be deleted can be a right child.
Presented & Prepared by: Mahmoud R. Alfarra

4. Deleting a Node With One Child4 5 5 2 45 2 45
Node to
be deleted 30
Node to
be deleted 30 10 10
Presented & Prepared by: Mahmoud R. Alfarra

5. Deleting a Node With One Child5
Presented & Prepared by: Mahmoud R. Alfarra

6. Deleting a Node With Two Children6
Deletion now gets tricky when we have to delete a node with two children.
If we need to delete the node marked 52.We can’t replace it with the subtree starting at the node marked 54 because 54 already has a left child.
The answer to this problem is to …
Presented & Prepared by: Mahmoud R. Alfarra

7. Delete (with two children)6 2 8 1 5 3 4 6 3 8 1 5 4
delete (3)
Replace data of the node (2) with the smallest data of its right subtree (3) and delete that node (3) from the right subtree

8. Deleting a Node With Two Children8
Move the inorder successor into the place of the deleted node.
Presented & Prepared by: Mahmoud R. Alfarra

9. Finding the successor 9
Presented & Prepared by: Mahmoud R. Alfarra

10. Deleting a Node With Two Children10
We have two special cases:
The successor is the right child of the node to be deleted.
The successor is the left child of the node to be deleted.
Presented & Prepared by: Mahmoud R. Alfarra

11. قولوا لا إله إلا الله تُفلحـوا
Emank X Mezank !!
قال النبي صلى الله عليه وسلم:
قولوا لا إله إلا الله تُفلحـوا

12. Next Lecture
Hashing