insufficient-nodes-in-root-to-leaf-paths.go

package problem1080

import (
	"github.com/aQuaYi/LeetCode-in-Go/kit"
)

// TreeNode is pre-defined...
// type TreeNode struct {
//     Val int
//     Left *TreeNode
//     Right *TreeNode
// }
type TreeNode = kit.TreeNode

func sufficientSubset(root *TreeNode, limit int) *TreeNode {
	if root == nil {
		return nil
	}
	if root.Left == root.Right { // both nil
		if root.Val < limit {
			return nil
		}
		return root
	}
	limit -= root.Val
	root.Left = sufficientSubset(root.Left, limit)
	root.Right = sufficientSubset(root.Right, limit)
	if root.Left == root.Right { // both nil
		return nil
	}
	return root
}