C++ solution for Balanced Binary Tree

C++/balanced-binary-tree.cpp

@@ -0,0 +1,58 @@
+// Time: O(n)
+// Space: O(n)
+
+/**
+ * Definition for a binary tree node.
+ * 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:
+    int balanceHelper(TreeNode* node, bool& balanced){
+        int leftBal = 0;
+        int rightBal = 0;
+
+        if(node->left != nullptr){
+            leftBal = balanceHelper(node->left, balanced);
+        }
+        if(node->right != nullptr){
+            rightBal = balanceHelper(node->right, balanced);
+        }
+
+        if(leftBal - rightBal > 1 || leftBal - rightBal < -1){
+            balanced = false;
+        }
+
+        if(leftBal > rightBal){
+            return 1 + leftBal;
+        }
+        else{
+            return 1 + rightBal;
+        }
+    }
+
+
+    bool isBalanced(TreeNode* root) {
+        if(root != nullptr){
+            bool balanced = true;
+            balanceHelper(root, balanced);
+
+            if(!balanced){
+                return false;
+            }
+            else{
+                return true;
+            }
+        }
+        else{
+            return true;
+        }
+    }
+};