Balanced Tree

To determine if a binary tree is balanced, we can use a recursive approach. For each node, we need to check two conditions:

1. The left and right subtrees are themselves balanced.
2. The difference in height between the left and right subtrees is no more than 1.

We can implement this by creating a helper function that returns both the height of the subtree rooted at the current node and a boolean indicating whether that subtree is balanced. If at any point a subtree is found to be unbalanced, we can propagate this information up the recursion chain. The base case for the recursion is a null node, which is considered balanced and has a height of -1 (or 0, depending on convention).

This approach ensures that we visit each node only once, resulting in an O(n) time complexity, where n is the number of nodes in the tree. The space complexity is O(h) due to the recursion stack, where h is the height of the tree.