530. Minimum Absolute Difference in BST

530. Minimum Absolute Difference in BST

 

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def getMinimumDifference(self, root: Optional[TreeNode]) -> int:
        # BST 이므로, inorder (좌, 현재, 우) 로 출력하면, 작->큰, 오름차순으로 값이 나옴
        arr = []
        def inorder(node):
            if node.left:
                inorder(node.left)

            arr.append(node.val)

            if node.right:
                inorder(node.right)

        inorder(root)

        minima = float("inf")
        for i in range(len(arr)-1):
            minima = min(minima, arr[i+1]-arr[i])
        return minima