Create 543. Diameter of Binary Tree (#418)

Author: Chayandas07

543. Diameter of Binary Tree

@@ -0,0 +1,27 @@
+
+/**
+ * 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 mx = 0;
+    int solve(TreeNode* root){
+        if(root == NULL) return 0;
+        int l = solve(root->left), r = solve(root->right);
+        mx = max(mx, l + r);
+        return 1 + max(l, r);
+    }
+    int diameterOfBinaryTree(TreeNode* root) {
+        solve(root);
+        return mx;
+    }
+};