add Count Non Leaf Nodes of Tree

algorithms/CPlusPlus/Trees/Count-Non-Leaf-Nodes.cpp

@@ -0,0 +1,76 @@
+
+
+/* QUESTION->
+Given a Binary Tree of size N, your task is to complete the function countNonLeaf TreeNodes(), that should return the count of all the non-leaf  TreeNodes of the given binary tree.
+*/
+
+
+    /* Prerequisites
+        Recursion
+        Post-Order Traversal 
+    */
+
+    /* Complexity
+        Time -> O(n);
+        space -> O(Height of tree);
+    */
+
+   // Instructions  -> just copy to run
+
+#include<bits/stdc++.h>
+using namespace std;
+
+// Basic Structure of a Tree
+struct  TreeNode {
+    int data;
+    struct   TreeNode *left;
+    struct   TreeNode *right;
+
+     TreeNode(int val) {
+        data = val;
+        left = NULL;
+        right = NULL;
+    }
+};
+
+
+//Function to calculate  to count  non-Leaf  of Tree
+int countNonLeaf ( TreeNode* root) {
+        if(root==NULL){
+            return 0;
+        }
+        int sum=0;
+
+        sum+= countNonLeaf(root->left);
+        
+        sum+=countNonLeaf(root->right);
+        
+         if(root->left!=NULL || root->right!=NULL){
+              sum++;
+         }
+         return sum;
+    }
+
+
+
+int main(){
+     TreeNode* root = new  TreeNode(1);
+    root->left = new  TreeNode(2);
+    root->right = new  TreeNode(3);
+    root->left->left = new  TreeNode(4);
+    root->left->right = new   TreeNode(5);
+    root->right->right = new  TreeNode(7);
+
+    /*
+                    1----non leaf Node=1
+                   / \
+                  2   3----non leaf Nodes =2
+                 / \   \
+                4   5   7----non leaf Nodes=0
+
+             Expected ans-> height=3
+    */
+    cout << "Count of non leaf nodes of tree is : " << countNonLeaf(root) << '\n';
+
+    return 0;
+}