diff --git a/Backtracking/Diameter (Node-count) of binary tree (Un-optimized).cpp b/Backtracking/Diameter (Node-count) of binary tree (Un-optimized).cpp
new file mode 100644
index 0000000..fb459d6
--- /dev/null
+++ b/Backtracking/Diameter (Node-count) of binary tree (Un-optimized).cpp	
@@ -0,0 +1,73 @@
+#include <bits/stdc++.h>
+using namespace std;
+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) {}
+};
+// there will be three cases, the diameter may pass through root
+//secondly, the diameter would only be in the left part of rootnode
+// or the diameter would only be in right part of root node;
+// Note that the root node of subtree is also called root node,
+// The diameter of all leaf nodes are zeros,
+// and height of every node is retuned in ls or rs,
+// which are used to find
+// height and then diamater.
+
+// when the dia is calculated as the number of nodes (farthest Nodes), then ony 1 will be added to sum of height of left subtree and right sub tree.
+// bcz there is only one node b/w left and right sub tree;
+
+// BUt in case of edge count (dia= no.of edges b/w farthest nodes) then 2 will be added to sum of height of left subtree and right sub tree.
+// bcz there are two edges b/w left and right subtree from root node (one edge to left and other to right)
+
+TreeNode *BuildTree()
+{
+    int d;
+    cin >> d;
+    if (d == -1)
+        return NULL;
+    TreeNode *Node = new TreeNode(d);
+    Node->left = BuildTree();
+    Node->right = BuildTree();
+    return Node;
+}
+void print(TreeNode *root)
+{
+    if (root == NULL)
+        return;
+    cout << root->val << " ";   
+    print(root->left);
+
+    print(root->right);
+}
+int height(TreeNode *root)
+{
+    if (root == NULL)
+        return 0;
+    int ls = height(root->left);
+    int rs = height(root->right);
+    return max(ls, rs) + 1;
+}
+int diameter(TreeNode *root)
+{
+    if (root == NULL)
+        return 0;
+    int lh = height(root->left);
+    int rh = height(root->right);
+    int op1 = lh + rh + 1;
+    int op2 = diameter(root->left);
+    int op3 = diameter(root->right);
+    return max(op1, max(op2, op3));
+}
+int main()
+{
+    TreeNode *root = BuildTree();
+    cout << "PreOrder of Tree is: ";
+    print(root);
+    cout << endl;
+    cout << "The daimeter of binary tree : " << diameter(root);
+}