[LeetCode] Balanced Binary Tree in Objective C

LeetCode: Balanced Binary Tree in Objective C

typedef struct {
    int value;
    struct TreeNode *left;
    struct TreeNode *right;
 } TreeNode;

- (BOOL)isBalanced:(TreeNode *)node
{
     if (!node) return true;
     return (abs(maximumDepth(node.left)-maximumDepth(node.right)) <=1
             && isBalanced(node.left)
             && isBalanced(node.right);
}

- (int)maximumDepth:(TreeNode *)node
{
    if (!node) return 0;
    return MAX(maximumDepth(node.left), maximumDepth(node.right)) + 1;
}