# Balanced Binary Tree Problem & Solution

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 left and right subtrees of every node differ in height by no more than 1.

## C++ Solution

``````#pragma GCC optimize("Ofast")
#pragma GCC optimization("max-inline-insns-recursive-auto")

static const int _=[](){std::ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();

/**
* struct TreeNode {
*   int val;
*   TreeNode *left;
*   TreeNode *right;
*   TreeNode() : val(0), left(nullptr), right(nullptr) {}
*   TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
*   TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
bool isBalanced(TreeNode* root) {
bool ok = true;

isBalanced(root, ok);

return ok;
}

private:
int isBalanced(TreeNode* root, bool& ok) {
if (root == nullptr) {
return 0;
}

int left = isBalanced(root->left, ok);
int right = isBalanced(root->right, ok);

if (abs(left - right) > 1) {
ok = false;
}

return max(left, right) + 1;
}
};
``````