Create 40 Diameter of binary tree.cpp

Author: skjha1

src/Algorithms/Dynamic Programming/40 Diameter of binary tree.cpp

@@ -0,0 +1,36 @@
+/**
+ * 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 {
+private:
+    int res;
+public:
+    int Solve(TreeNode* root) {
+        if (root == NULL)
+            return 0;
+
+        int l = Solve(root->left);
+        int r = Solve(root->right);
+
+        int temp = 1 + max(l, r);
+        int ans = max(temp, l + r + 1);
+        res = max(res, ans);
+        return temp;
+    }
+    int diameterOfBinaryTree(TreeNode* root) {
+        if (root == NULL)
+            return 0;
+
+        res = INT_MIN + 1;
+        Solve(root);
+        return res - 1;
+    }
+};