# 15.06.2023 [1161. Maximum Level Sum of a Binary Tree]

Binary Tree level with max sum

15.06.2023

1161. Maximum Level Sum of a Binary Tree medium
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Problem TLDR

Binary Tree level with max sum

Intuition

We can use Breadth-First Search to find a sum of each level.

Approach

Let’s try to write it in a Kotlin style

Complexity

• Time complexity:
  O(n)

• Space complexity:
  O(n)

Code

fun maxLevelSum(root: TreeNode?) = with(ArrayDeque<TreeNode>()) {
    root?.let { add(it) }
    generateSequence<Int> {
        if (isEmpty()) null else (1..size).map {
            with(poll()) {
                `val`.also {
                    left?.let { add(it) }
                    right?.let { add(it) }
                }
            }
        }.sum()
    }.withIndex().maxBy { it.value }?.index?.inc() ?: 0
}