2331. Evaluate Boolean Binary Tree

Easy
You are given the root of a full binary tree with the following properties:
  • Leaf nodes have either the value 0 or 1, where 0 represents False and 1 represents True.
  • Non-leaf nodes have either the value 2 or 3, where 2 represents the boolean OR and 3 represents the boolean AND.
The evaluation of a node is as follows:
  • If the node is a leaf node, the evaluation is the value of the node, i.e. True or False.
  • Otherwise, evaluate the node's two children and apply the boolean operation of its value with the children's evaluations.
Return the boolean result of evaluating the root node.
A full binary tree is a binary tree where each node has either 0 or 2 children.
A leaf node is a node that has zero children.
Example 1:
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Input: root = [2,1,3,null,null,0,1]
Output: true
Explanation: The above diagram illustrates the evaluation process.
The AND node evaluates to False AND True = False.
The OR node evaluates to True OR False = True.
The root node evaluates to True, so we return true.
Example 2:
Input: root = [0]
Output: false
Explanation: The root node is a leaf node and it evaluates to false, so we return false.
Constraints:
  • The number of nodes in the tree is in the range [1, 1000].
  • 0 <= Node.val <= 3
  • Every node has either 0 or 2 children.
  • Leaf nodes have a value of 0 or 1.
  • Non-leaf nodes have a value of 2 or 3.

解題

/**
* Definition for a binary tree node.
* type TreeNode struct {
* Val int
* Left *TreeNode
* Right *TreeNode
* }
*/
func evaluateTree(root *TreeNode) bool {
if root.Val == 0 {
return false
} else if root.Val == 1 {
return true
} else if root.Val == 2 {
return evaluateTree(root.Left) || evaluateTree(root.Right)
}
​
return evaluateTree(root.Left) && evaluateTree(root.Right)
}
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