Maddhapara Granite Mining Company Limited
Post: Assistant Engineer
Exam Date: 20/05/2022, Exam Taker: BUET
In a Binary Search Tree (BST), each node can have up to two child nodes: a left child and a right child. The left child always holds a value that is less than its parent node, while the right child holds a value that is greater than its parent node. This property ensures that for any given node in the tree, all values in the left subtree are smaller, and all values in the right subtree are larger than the node’s value.
Input Set: [50, 30, 70, 20, 40, 60, 80]The BST constructed from these numbers will look like: 50
/ \
30 70
/ \ / \
20 40 60 80
Pre-order Traversal (Root, Left, Right)
In pre-order traversal, we visit the root first, then traverse the left subtree, and finally the right subtree.
For the above BST:[50, 30, 20, 40, 70, 60, 80]
Post-order Traversal (Left, Right, Root)
In post-order traversal, we traverse the left subtree first, then the right subtree, and visit the root last.
For above BST: [20, 40, 30, 60, 80, 70, 50]
Deleting a NodeLet’s delete the node with the value 30.Steps to delete a node in a BST:- Find the node (30).
- If it has two children (as node 30 does), find the in-order successor (smallest node in the right subtree), which is 40.
- Replace the value of node 30 with 40 and delete the in-order successor node (40).
50
/ \
40 70
/ / \
20 60 80
1. Show All Hidden Files
Use the following command to list all files, including hidden files:
ls -a
2. Remove a File
To delete a file, use the command below. Replace filename with the actual file name:
rm filename
3. Change File Permissions
To set permissions for a file, use this command. Replace filename with the file name:
chmod 777 filename
This command grants read, write, and execute permissions to all users.
4. Search for a String in Files
To search for a specific string within files, use the command below. Replace /path/to/directory/ with the directory path and pattern with the string to search for:
grep -rnw '/path/to/directory/' -e 'pattern'
Options:
-r: Makes the search recursive through all files in the directory.-n: Displays the line numbers where the pattern is found.-w: Matches whole words only.
