BinaryTree_LevelOrder_Printing.cpp

#include <iostream>
#include<queue>
using namespace std;

class node{
    public:
        int data;
        node*left;
        node*right;

        node(int d){
            data = d;
            left = NULL;
            right = NULL;
        }
};

node* buildTree(){
    int d;
    cin>>d;

    if(d==-1){
        return NULL;
    }
    node * root = new node(d);
    root->left = buildTree();
    root->right = buildTree();
    return root;
}


void bfs(node *root){
    queue<node*> q;
    q.push(root);

    while(!q.empty()){
        node* f = q.front();
        cout<<f->data<<",";
        q.pop();

        if(f->left){
            q.push(f->left);
        }
        if(f->right){
            q.push(f->right);
        }
    }
    return;
}
void LevelOrderPrint(node* root)
{
    queue<node*> q;
    q.push(root);
    q.push(NULL);

    while(!q.empty())
    {
        node* temp =q.front();
        q.pop();

        if(temp==NULL)
        {
            cout<<endl;

            if(!q.empty())
            {
                q.push(NULL);
            }
        }
        else
        {
            cout<<temp->data<<" ";
            if(temp->left)
            {
                q.push(temp->left);
            }
            if(temp->right)
            {
                q.push(temp->right);
            }
        }
    }
    return;
}
int  SumofNodes(node*root)
{
    if(root==NULL)
    {
        return 0;
    }

    return (root->data+SumofNodes(root->left)+SumofNodes(root->right)+1);
}



int main(){
    node* root = buildTree();
    //cout<<count(root)<<endl;
    //printAllLevels(root);
    //bfs(root);
    //LevelOrderPrint(root);
    cout<<SumofNodes(root);

return 0;
}