# Print all nodes except rightmost node of every level of the Binary Tree

Given a binary tree, the task is to print all the nodes except the rightmost in every level of the tree. The root is considered at level 0, and rightmost node of any level is considered as a node at position 0.

Examples:

```Input:
1
/     \
2       3
/   \       \
4     5       6
/  \
7    8
/      \
9        10

Output:
2
4 5
7
9

Input:
1
/   \
2     3
\     \
4     5
Output:
2
4```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: To print nodes level by level, use level order traversal. The idea is based on Print level order traversal line by line. For that, traverse nodes level by level and if the node in the queue of level order is the last node then that node will be the rightmost node and don’t print that node.

Below is the implementation of the above approach:

 `// C++ implementation of the approach ` `#include ` `using` `namespace` `std; ` ` `  `// Structure of the tree node ` `struct` `Node { ` `    ``int` `data; ` `    ``Node *left, *right; ` `}; ` ` `  `// Utility method to create a node ` `struct` `Node* newNode(``int` `data) ` `{ ` `    ``struct` `Node* node = ``new` `Node; ` `    ``node->data = data; ` `    ``node->left = node->right = NULL; ` `    ``return` `(node); ` `} ` ` `  `// Function to print all the nodes ` `// except the rightmost in every level ` `// of the given binary tree ` `// with level order traversal ` `void` `excluderightmost(Node* root) ` `{ ` `    ``// Base Case ` `    ``if` `(root == NULL) ` `        ``return``; ` ` `  `    ``// Create an empty queue for level ` `    ``// order traversal ` `    ``queue q; ` ` `  `    ``// Enqueue root ` `    ``q.push(root); ` ` `  `    ``while` `(1) { ` ` `  `        ``// nodeCount (queue size) indicates ` `        ``// number of nodes at current level. ` `        ``int` `nodeCount = q.size(); ` `        ``if` `(nodeCount == 0) ` `            ``break``; ` ` `  `        ``// Dequeue all nodes of current level ` `        ``// and Enqueue all nodes of next level ` `        ``while` `(nodeCount > 0) { ` `            ``Node* node = q.front(); ` ` `  `            ``// If node is not rightmost print ` `            ``if` `(nodeCount != 1) ` `                ``cout << node->data << ``" "``; ` `            ``q.pop(); ` `            ``if` `(node->left != NULL) ` `                ``q.push(node->left); ` `            ``if` `(node->right != NULL) ` `                ``q.push(node->right); ` `            ``nodeCount--; ` `        ``} ` `        ``cout << ``"\n"``; ` `    ``} ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``struct` `Node* root = newNode(1); ` `    ``root->left = newNode(2); ` `    ``root->right = newNode(3); ` `    ``root->left->left = newNode(4); ` `    ``root->left->right = newNode(5); ` `    ``root->right->left = newNode(6); ` `    ``root->right->right = newNode(7); ` `    ``root->left->right->left = newNode(8); ` `    ``root->left->right->right = newNode(9); ` `    ``root->left->right->right->right = newNode(10); ` ` `  `    ``excluderightmost(root); ` ` `  `    ``return` `0; ` `} `

 `// Java implementation of the approach ` `import` `java.util.*; ` ` `  `class` `Sol { ` ` `  `    ``// Structure of the tree node ` `    ``static` `class` `Node { ` `        ``int` `data; ` `        ``Node left, right; ` `    ``}; ` ` `  `    ``// Utility method to create a node ` `    ``static` `Node newNode(``int` `data) ` `    ``{ ` `        ``Node node = ``new` `Node(); ` `        ``node.data = data; ` `        ``node.left = node.right = ``null``; ` `        ``return` `(node); ` `    ``} ` ` `  `    ``// Function to print all the nodes ` `    ``// except the rightmost in every level ` `    ``// of the given binary tree ` `    ``// with level order traversal ` `    ``static` `void` `excluderightmost(Node root) ` `    ``{ ` `        ``// Base Case ` `        ``if` `(root == ``null``) ` `            ``return``; ` ` `  `        ``// Create an empty queue for level ` `        ``// order traversal ` `        ``Queue q = ``new` `LinkedList(); ` ` `  `        ``// Enqueue root ` `        ``q.add(root); ` ` `  `        ``while` `(``true``) { ` ` `  `            ``// nodeCount (queue size) indicates ` `            ``// number of nodes at current level. ` `            ``int` `nodeCount = q.size(); ` `            ``if` `(nodeCount == ``0``) ` `                ``break``; ` ` `  `            ``// Dequeue all nodes of current level ` `            ``// and Enqueue all nodes of next level ` `            ``while` `(nodeCount > ``0``) { ` `                ``Node node = q.peek(); ` ` `  `                ``// If node is not rightmost print ` `                ``if` `(nodeCount != ``1``) ` `                    ``System.out.print(node.data + ``" "``); ` `                ``q.remove(); ` `                ``if` `(node.left != ``null``) ` `                    ``q.add(node.left); ` `                ``if` `(node.right != ``null``) ` `                    ``q.add(node.right); ` ` `  `                ``nodeCount--; ` `            ``} ` `            ``System.out.println(); ` `        ``} ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `main(String args[]) ` `    ``{ ` `        ``Node root = newNode(``1``); ` `        ``root.left = newNode(``2``); ` `        ``root.right = newNode(``3``); ` `        ``root.left.left = newNode(``4``); ` `        ``root.left.right = newNode(``5``); ` `        ``root.right.left = newNode(``6``); ` `        ``root.right.right = newNode(``7``); ` `        ``root.left.right.left = newNode(``8``); ` `        ``root.left.right.right = newNode(``9``); ` `        ``root.left.right.right.right = newNode(``10``); ` ` `  `        ``excluderightmost(root); ` `    ``} ` `} `

 `# Python implementation of the approach  ` `from` `collections ``import` `deque  ` `    `  `# Structure of the tree node  ` `class` `Node:  ` `    ``def` `__init__(``self``):  ` `        ``self``.data ``=` `0` `        ``self``.left ``=` `None` `        ``self``.right ``=` `None` `    `  `# Utility method to create a node  ` `def` `newNode(data: ``int``) ``-``> Node:  ` `    ``node ``=` `Node()  ` `    ``node.data ``=` `data  ` `    ``node.left ``=` `None` `    ``node.right ``=` `None` `    ``return` `node  ` `    `  `# Function to print all the nodes  ` `# except the rightmost in every level  ` `# of the given binary tree  ` `# with level order traversal  ` `def` `excluderightmost(root: Node):  ` `    `  `    ``# Base Case  ` `    ``if` `root ``is` `None``:  ` `        ``return` `    `  `    ``# Create an empty queue for level  ` `    ``# order traversal  ` `    ``q ``=` `deque()  ` `    `  `    ``# Enqueue root  ` `    ``q.append(root)  ` `    `  `    ``while` `1``:  ` `    `  `        ``# nodeCount (queue size) indicates  ` `        ``# number of nodes at current level  ` `        ``nodeCount ``=` `len``(q)  ` `        ``if` `nodeCount ``=``=` `0``:  ` `            ``break` `    `  `        ``# Dequeue all nodes of current level  ` `        ``# and Enqueue all nodes of next level  ` `        ``while` `nodeCount > ``0``:  ` `            ``node ``=` `q[``0``]  ` `    `  `            ``# If Node is not right most print ` `            ``if` `nodeCount !``=` `1``:  ` `                ``print``(node.data, end ``=``" "``)  ` `            ``q.popleft()  ` `              `  `            ``if` `node.left ``is` `not` `None``:  ` `                ``q.append(node.left)  ` `            ``if` `node.right ``is` `not` `None``:  ` `                ``q.append(node.right)  ` `              `  `            ``nodeCount ``-``=` `1` `        ``print``()  ` `    `  `# Driver Code  ` `if` `__name__ ``=``=` `"__main__"``:  ` `    ``root ``=` `Node()  ` `    ``root ``=` `newNode(``1``)  ` `    ``root.left ``=` `newNode(``2``)  ` `    ``root.right ``=` `newNode(``3``)  ` `    ``root.left.left ``=` `newNode(``4``)  ` `    ``root.left.right ``=` `newNode(``5``)  ` `    ``root.right.left ``=` `newNode(``6``)  ` `    ``root.right.right ``=` `newNode(``7``)  ` `    ``root.left.right.left ``=` `newNode(``8``)  ` `    ``root.left.right.right ``=` `newNode(``9``)  ` `    ``root.left.right.right.right ``=` `newNode(``10``)  ` `    ``excluderightmost(root) `

 `// C# implementation of the above approach ` `using` `System; ` `using` `System.Collections.Generic; ` ` `  `class` `GFG { ` ` `  `    ``// Structure of the tree node ` `    ``public` `class` `Node { ` `        ``public` `int` `data; ` `        ``public` `Node left, right; ` `    ``}; ` ` `  `    ``// Utility method to create a node ` `    ``static` `Node newNode(``int` `data) ` `    ``{ ` `        ``Node node = ``new` `Node(); ` `        ``node.data = data; ` `        ``node.left = node.right = ``null``; ` `        ``return` `(node); ` `    ``} ` ` `  `    ``// Function to print all the nodes ` `    ``// except the rightmost in every level ` `    ``// of the given binary tree ` `    ``// with level order traversal ` `    ``static` `void` `excluderightmost(Node root) ` `    ``{ ` `        ``// Base Case ` `        ``if` `(root == ``null``) ` `            ``return``; ` ` `  `        ``// Create an empty queue for level ` `        ``// order traversal ` `        ``Queue q = ``new` `Queue(); ` ` `  `        ``// Enqueue root ` `        ``q.Enqueue(root); ` ` `  `        ``while` `(``true``) { ` ` `  `            ``// nodeCount (queue size) indicates ` `            ``// number of nodes at current level. ` `            ``int` `nodeCount = q.Count; ` `            ``if` `(nodeCount == 0) ` `                ``break``; ` ` `  `            ``// Dequeue all nodes of current level ` `            ``// and Enqueue all nodes of next level ` `            ``while` `(nodeCount > 0) { ` `                ``Node node = q.Peek(); ` ` `  `                ``// if Node is not right most print ` `                ``if` `(nodeCount != 1) ` `                    ``Console.Write(node.data + ``" "``); ` `                ``q.Dequeue(); ` `                ``if` `(node.left != ``null``) ` `                    ``q.Enqueue(node.left); ` `                ``if` `(node.right != ``null``) ` `                    ``q.Enqueue(node.right); ` ` `  `                ``nodeCount--; ` `            ``} ` `            ``Console.WriteLine(); ` `        ``} ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `Main(String[] args) ` `    ``{ ` `        ``Node root = newNode(1); ` `        ``root.left = newNode(2); ` `        ``root.right = newNode(3); ` `        ``root.left.left = newNode(4); ` `        ``root.left.right = newNode(5); ` `        ``root.right.left = newNode(6); ` `        ``root.right.right = newNode(7); ` `        ``root.left.right.left = newNode(8); ` `        ``root.left.right.right = newNode(9); ` `        ``root.left.right.right.right = newNode(10); ` ` `  `        ``excluderightmost(root); ` `    ``} ` `} `

Output:
```2
4 5 6
8
```

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