level_order_traversal.cpp

#include <bits/stdc++.h>
using namespace std;

struct Node  
{ 
  int key; 
  struct Node *left; 
  struct Node *right; 
  Node(int k){
      key=k;
      left=right=NULL;
  }
};

void printLevel(Node *root){
    if(root==NULL)return;
    queue<Node *>q;
    q.push(root);
    while(q.empty()==false){
        Node *curr=q.front();
        q.pop();
        cout<<curr->key<<" ";
        if(curr->left!=NULL)
            q.push(curr->left);
        if(curr->right!=NULL)
            q.push(curr->right);
    }
}  

int main() {
	
	Node *root=new Node(10);
	root->left=new Node(20);
	root->right=new Node(30);
	root->left->left=new Node(40);
	root->left->right=new Node(50);
	root->right->left=new Node(60);
	root->right->right=new Node(70);
	
	printLevel(root);
}