BinaryTreeRepresentation.cpp

/*
You are given an array nodes. It contains 7 integers, which represents the value of nodes of the binary tree in level order traversal. You are also given a root of the tree which has a value equal to nodes[0].
Your task to construct a binary tree by creating nodes for the remaining 6 nodes.

Example:
Input:
nodes = [1 2 3 4 5 6 7]
Output:
         1
       /   \
     2       3
   /  \     /  \
   4  5    6   7
Explanation:
The 7 node binary tree is represented above.
Your Task:

Complete the function void create_tree(node* root0, vector &vec), which takes a root of a Binary tree and vector array vec containing the values of nodes.
Expected Time Complexity: O(1).
Expected Auxiliary Space: O(1).

Constraints:
vec.length = 7
1<=vec[i]<=100
*/

/// Queue based

//User function Template for C++

/*struct node {
  int data;
  struct node *left;
  struct node *right;
};

struct node *newNode(int data) {
  struct node *node = (struct node *)malloc(sizeof(struct node));

  node->data = data;

  node->left = NULL;
  node->right = NULL;
  return (node);
}*/

class Solution{
public:

    void create_tree(node* root0, vector<int> &vec){
        queue<node*> q;
        q.push(root0);
        for(int i=1;i<vec.size();i+=2){
            auto it = q.front();
            q.pop();
            it->left=newNode(vec[i]);
            q.push(it->left);
            it->right=newNode(vec[i+1]);
            q.push(it->right);
        }
    }

};