删除树状结构中过多的关系

class TreeNode:
    def __init__(self, value):
        self.value = value
        self.left = None
        self.right = None

def delete_redundant_relations(root):
    if not root:
        return None
    
    # 删除左子树的冗余关系
    root.left = delete_redundant_relations(root.left)
    
    # 删除右子树的冗余关系
    root.right = delete_redundant_relations(root.right)
    
    # 如果当前节点是叶子节点，直接返回
    if not root.left and not root.right:
        return root
    
    # 如果当前节点只有一个子节点，删除另一个子节点
    if not root.left:
        return root.right
    if not root.right:
        return root.left
    
    # 如果当前节点有两个子节点，保留左子树
    return root

# 示例用法
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)
root.left.left.left = TreeNode(6)  # 冗余关系

root = delete_redundant_relations(root)