Class Node
java.lang.Object
g0501_0600.s0558_logical_or_of_two_binary_grids_represented_as_quad_trees.Node
558 - Logical OR of Two Binary Grids Represented as Quad-Trees\.
Medium
A Binary Matrix is a matrix in which all the elements are either **0** or **1**.
Given `quadTree1` and `quadTree2`. `quadTree1` represents a `n * n` binary matrix and `quadTree2` represents another `n * n` binary matrix.
Return _a Quad-Tree_ representing the `n * n` binary matrix which is the result of **logical bitwise OR** of the two binary matrixes represented by `quadTree1` and `quadTree2`.
Notice that you can assign the value of a node to **True** or **False** when `isLeaf` is **False** , and both are **accepted** in the answer.
A Quad-Tree is a tree data structure in which each internal node has exactly four children. Besides, each node has two attributes:
* `val`: True if the node represents a grid of 1's or False if the node represents a grid of 0's.
* `isLeaf`: True if the node is leaf node on the tree or False if the node has the four children.
class Node {
public boolean val;
public boolean isLeaf;
public Node topLeft;
public Node topRight;
public Node bottomLeft;
public Node bottomRight;
}
We can construct a Quad-Tree from a two-dimensional area using the following steps:
1. If the current grid has the same value (i.e all `1's` or all `0's`) set `isLeaf` True and set `val` to the value of the grid and set the four children to Null and stop.
2. If the current grid has different values, set `isLeaf` to False and set `val` to any value and divide the current grid into four sub-grids as shown in the photo.
3. Recurse for each of the children with the proper sub-grid.
If you want to know more about the Quad-Tree, you can refer to the [wiki](https://en.wikipedia.org/wiki/Quadtree).
**Quad-Tree format:**
The input/output represents the serialized format of a Quad-Tree using level order traversal, where `null` signifies a path terminator where no node exists below.
It is very similar to the serialization of the binary tree. The only difference is that the node is represented as a list `[isLeaf, val]`.
If the value of `isLeaf` or `val` is True we represent it as **1** in the list `[isLeaf, val]` and if the value of `isLeaf` or `val` is False we represent it as **0**.
**Example 1:**
 
**Input:** quadTree1 = \[\[0,1],[1,1],[1,1],[1,0],[1,0]] , quadTree2 = \[\[0,1],[1,1],[0,1],[1,1],[1,0],null,null,null,null,[1,0],[1,0],[1,1],[1,1]]
**Output:** [[0,0],[1,1],[1,1],[1,1],[1,0]]
**Explanation:** quadTree1 and quadTree2 are shown above. You can see the binary matrix which is represented by each Quad-Tree. If we apply logical bitwise OR on the two binary matrices we get the binary matrix below which is represented by the result Quad-Tree. Notice that the binary matrices shown are only for illustration, you don't have to construct the binary matrix to get the result tree. 
**Example 2:**
**Input:** quadTree1 = \[\[1,0]], quadTree2 = \[\[1,0]]
**Output:** [[1,0]]
**Explanation:** Each tree represents a binary matrix of size 1\*1. Each matrix contains only zero. The resulting matrix is of size 1\*1 with also zero.
**Constraints:**
* `quadTree1` and `quadTree2` are both **valid** Quad-Trees each representing a `n * n` grid.
*
n == 2x where `0 <= x <= 9`.-
Field Summary
FieldsModifier and TypeFieldDescriptionbooleanboolean -
Constructor Summary
Constructors -
Method Summary