Added solution - LeetHub

Count Non-Leaf Nodes in Tree - GFG/count-non-leaf-nodes-in-tree.java

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+//{ Driver Code Starts
+//Initial template for JAVA
+
+import java.util.LinkedList; 
+import java.util.Queue; 
+import java.io.*;
+import java.util.*;
+
+class Node{
+    int data;
+    Node left;
+    Node right;
+    Node(int data){
+        this.data = data;
+        left=null;
+        right=null;
+    }
+}
+
+class GfG {
+
+    static Node buildTree(String str){
+
+        if(str.length()==0 || str.charAt(0)=='N'){
+            return null;
+        }
+
+        String ip[] = str.split(" ");
+        // Create the root of the tree
+        Node root = new Node(Integer.parseInt(ip[0]));
+        // Push the root to the queue
+
+        Queue<Node> queue = new LinkedList<>(); 
+
+        queue.add(root);
+        // Starting from the second element
+
+        int i = 1;
+        while(queue.size()>0 && i < ip.length) {
+
+            // Get and remove the front of the queue
+            Node currNode = queue.peek();
+            queue.remove();
+
+            // Get the current node's value from the string
+            String currVal = ip[i];
+
+            // If the left child is not null
+            if(!currVal.equals("N")) {
+
+                // Create the left child for the current node
+                currNode.left = new Node(Integer.parseInt(currVal));
+                // Push it to the queue
+                queue.add(currNode.left);
+            }
+
+            // For the right child
+            i++;
+            if(i >= ip.length)
+                break;
+
+            currVal = ip[i];
+
+            // If the right child is not null
+            if(!currVal.equals("N")) {
+
+                // Create the right child for the current node
+                currNode.right = new Node(Integer.parseInt(currVal));
+
+                // Push it to the queue
+                queue.add(currNode.right);
+            }
+            i++;
+        }
+
+        return root;
+    }
+    static void printInorder(Node root){
+        if(root == null)
+            return;
+
+        printInorder(root.left);
+        System.out.print(root.data+" ");
+
+        printInorder(root.right);
+    }
+
+	public static void main (String[] args) throws IOException {
+	        BufferedReader br= new BufferedReader(new InputStreamReader(System.in));
+
+	        int t=Integer.parseInt(br.readLine());
+	        while(t-- > 0){
+	            String s= br.readLine();
+	            Node root = buildTree(s);
+
+	            Solution tr=new Solution();
+	            int sum=tr.countNonLeafNodes(root);
+	            System.out.println(sum);
+	        }
+	}
+}
+// } Driver Code Ends
+
+
+//User function Template for Java
+
+/*class Node
+{
+    int data;
+    Node left,right;
+    Node(int d){
+        data=d;
+        left=right=null;
+    }
+}*/
+
+//function should return the count of total number of non leaf nodes in the tree.
+class Solution
+{  
+    int count=0;
+	int countNonLeafNodes(Node root) {
+	    if(root.left!=null || root.right!=null)
+	    {
+	        count++;
+	        if(root.left!=null)
+	        countNonLeafNodes(root.left);
+	        if(root.right!=null)
+	        countNonLeafNodes(root.right);
+	    }
+	    return(count);
+	}
+}