Maximum Path Sum in Binary Tree in DSA Go - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the TreeNode struct with integer value and pointers to left and right children.

DSA Go

type TreeNode struct {
    Val   int
    Left  *[1]
    Right *TreeNode
}

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ATreeNode

BNode

CTree

DNodeTree

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different struct name for Left or Right pointer.

Forgetting the pointer symbol * before the type.

The TreeNode struct has Left and Right fields that are pointers to TreeNode type.

2fill in blank

medium

Complete the code to return the maximum of two integers a and b.

DSA Go

func max(a, b int) int {
    if a [1] b {
        return a
    }
    return b
}

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A>

B<

C==

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' causing minimum to be returned.

Using '==' which only checks equality.

To find the maximum, return a if a is greater than b, else return b.

3fill in blank

hard

Fix the error in the recursive function to compute max path sum from a node.

DSA Go

func maxPathSumHelper(root *TreeNode, maxSum *int) int {
    if root == nil {
        return 0
    }
    left := max(0, maxPathSumHelper(root.Left, maxSum))
    right := max(0, maxPathSumHelper(root.Right, maxSum))
    *maxSum = max(*maxSum, root.Val + left + [1])
    return root.Val + max(left, right)
}

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Aleft

B0

Croot.Val

Dright

Attempts:

3 left

💡 Hint

Common Mistakes

Adding left twice instead of left and right.

Adding root.Val twice.

The max path sum through the current node includes root.Val plus left and right max sums.

4fill in blank

hard

Fill both blanks to complete the main function that initializes maxSum and calls the helper.

DSA Go

func maxPathSum(root *TreeNode) int {
    maxSum := [1]
    maxPathSumHelper(root, &[2])
    return maxSum
}

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Amath.MinInt32

BmaxSum

C0

D-100000

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing maxSum to 0 which fails for all negative nodes.

Passing maxSum instead of its address.

Initialize maxSum to the smallest integer to handle negative values. Pass its address to helper.

5fill in blank

hard

Fill all three blanks to complete the max function and import statement.

DSA Go

import (
    "fmt"
    "[1]"
)

func max(a, b int) int {
    if a [2] b {
        return a
    }
    return [3]
}

func main() {
    fmt.Println(max(10, 20))
}

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Amath

B>

Cb

Dfmt

Attempts:

3 left

💡 Hint

Common Mistakes

Importing wrong package.

Using wrong comparison operator.

Returning a instead of b.

Import math package. Use '>' to compare a and b. Return b if a is not greater.