[CPP] 104. Maximum Depth of Binary Tree

Author: UnresolvedCold

cpp/104-Maximum-Depth-of-Binary-Tree.cpp

@@ -0,0 +1,40 @@
+/**
+ * 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) {}
+ * };
+ */
+
+// Using Stack
+// class Solution {
+// public:
+//     int maxDepth(TreeNode* root) {
+//         if (root == NULL) return 0;
+//         stack<pair<TreeNode*, int>> stk;
+//         int res = 0; 
+//         stk.push({root, 1});
+        
+//         while (!stk.empty()) {
+//             auto t = stk.top();
+//             res = max(res, t.second);
+//             stk.pop();
+//             if (t.first->left) stk.push({t.first->left, t.second+1});
+//             if (t.first->right) stk.push({t.first->right, t.second+1});
+//         }
+//         return res;
+//     }
+// };
+
+// Using Recursion
+class Solution {
+public:
+    int maxDepth(TreeNode* root) {
+        if (root == NULL) return 0;
+        return max(maxDepth(root->left)+1, maxDepth(root->right)+1);
+    }
+};