Morris Traversal Inorder Without Stack in DSA Go - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to move to the left child in Morris Traversal.

DSA Go

current = root
for current != nil {
    if current.Left == nil {
        fmt.Println(current.Val)
        current = current[1]
    } else {
        // Find the inorder predecessor
    }
}

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

A.Parent

B.Left

C.Right

D.Next

Attempts:

3 left

💡 Hint

Common Mistakes

Moving to .Left instead of .Right causes infinite loop.

Using .Parent or .Next which are not standard pointers in this context.

In Morris Traversal, when the left child is nil, we print the current node and move to its right child.

2fill in blank

medium

Complete the code to find the inorder predecessor in Morris Traversal.

DSA Go

predecessor := current.Left
for predecessor.Right != nil && predecessor.Right != current {
    predecessor = predecessor[1]
}

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

A.Right

B.Next

C.Parent

D.Left

Attempts:

3 left

💡 Hint

Common Mistakes

Moving left instead of right causes incorrect predecessor.

Using .Parent or .Next which are not relevant here.

The inorder predecessor is the rightmost node in the left subtree, so we move right until nil or current.

3fill in blank

hard

Fix the error in setting the thread link in Morris Traversal.

DSA Go

if predecessor.Right == nil {
    predecessor.Right = current
    current = current[1]
}

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

A.Next

B.Right

C.Parent

D.Left

Attempts:

3 left

💡 Hint

Common Mistakes

Moving right causes infinite loop.

Using .Parent or .Next which are invalid pointers.

After setting the thread, move to the left child to continue traversal.

4fill in blank

hard

Fill both blanks to remove the thread and move to the right child in Morris Traversal.

DSA Go

else {
    predecessor.Right = [1]
    fmt.Println(current.Val)
    current = current[2]
}

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

Anil

B.Left

C.Right

Dcurrent

Attempts:

3 left

💡 Hint

Common Mistakes

Setting predecessor.Right to current causes infinite loop.

Moving left instead of right after removing thread.

Remove the thread by setting predecessor.Right to nil, then move to current's right child.

5fill in blank

hard

Fill all three blanks to complete the Morris Traversal inorder function.

DSA Go

func morrisInorder(root *Node) {
    current := root
    for current != nil {
        if current.Left == nil {
            fmt.Println(current.Val)
            current = current[1]
        } else {
            predecessor := current.Left
            for predecessor.Right != nil && predecessor.Right != current {
                predecessor = predecessor[2]
            }
            if predecessor.Right == nil {
                predecessor.Right = current
                current = current[3]
            } else {
                predecessor.Right = nil
                fmt.Println(current.Val)
                current = current.Right
            }
        }
    }
}

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

A.Right

B.Left

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing left and right pointers causes incorrect traversal.

Not removing thread properly leads to infinite loops.

Move right when no left child, move right to find predecessor, move left after threading.