Tree Traversal Preorder Root Left Right in DSA Go - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the root node's value first in preorder traversal.

DSA Go

func preorder(node *Node) {
    if node == nil {
        return
    }
    fmt.Println(node.[1])
}

Drag options to blanks, or click blank then click option'

ARight

BLeft

CValue

DParent

Attempts:

3 left

💡 Hint

Common Mistakes

Printing node.Left or node.Right instead of node.Value.

Trying to print node.Parent which may not exist.

In preorder traversal, we visit the root node first, so we print node.Value.

2fill in blank

medium

Complete the code to recursively traverse the left subtree in preorder.

DSA Go

func preorder(node *Node) {
    if node == nil {
        return
    }
    fmt.Println(node.Value)
    preorder(node.[1])
}

Drag options to blanks, or click blank then click option'

ARight

BLeft

CParent

DValue

Attempts:

3 left

💡 Hint

Common Mistakes

Calling preorder on node.Right instead of node.Left.

Calling preorder on node.Value which is not a node.

After visiting the root, preorder traversal visits the left subtree by calling preorder(node.Left).

3fill in blank

hard

Fix the error in the code to correctly traverse the right subtree in preorder.

DSA Go

func preorder(node *Node) {
    if node == nil {
        return
    }
    fmt.Println(node.Value)
    preorder(node.Left)
    preorder(node.[1])
}

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ALeft

BValue

CParent

DRight

Attempts:

3 left

💡 Hint

Common Mistakes

Calling preorder on node.Value or node.Parent instead of node.Right.

Calling preorder on node.Left twice.

After visiting the left subtree, preorder traversal visits the right subtree by calling preorder(node.Right).

4fill in blank

hard

Fill both blanks to print the root node's value first and then recursively traverse the left subtree in preorder.

DSA Go

func preorder(node *Node) {
    if node == nil {
        return
    }
    fmt.Println(node.[1])
    preorder(node.[2])
}

Drag options to blanks, or click blank then click option'

AValue

BLeft

CRight

DParent

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping left and right child calls.

Printing node.Left instead of node.Value.

First print the root's value with node.Value, then recursively traverse the left subtree with preorder(node.Left).

5fill in blank

hard

Fill all three blanks to complete the preorder traversal visiting root, left, then right.

DSA Go

func preorder(node *Node) {
    if node == nil {
        return
    }
    fmt.Println(node.[1])
    preorder(node.[2])
    preorder(node.[3])
}

Drag options to blanks, or click blank then click option'

AValue

BLeft

CRight

DParent

Attempts:

3 left

💡 Hint

Common Mistakes

Calling preorder on node.Parent which is incorrect.

Mixing up left and right child calls.

Preorder traversal visits the root node's value, then recursively visits the left subtree, then the right subtree.