Balanced_Binary_Tree.cpp

// Given a binary tree, determine if it is height-balanced.

// For this problem, a height-balanced binary tree is defined as a binary tree in 
// which the depth of the two subtrees of every node never differ by more than 1.

class Solution {
public:
    int maxDepth(TreeNode *root) {
        if (root == NULL)
            return 0;
        return 1 + max(maxDepth(root->left), maxDepth(root->right));
    }

    bool isBalanced(TreeNode *root) {
        if (root == NULL)
            return true;
        if (abs(maxDepth(root->left) - maxDepth(root->right)) > 1)
            return false;
        return (isBalanced(root->left) && isBalanced(root->right));
    }
};