558. 四叉树交集

/*
// Definition for a QuadTree node.
class Node {
    public boolean val;
    public boolean isLeaf;
    public Node topLeft;
    public Node topRight;
    public Node bottomLeft;
    public Node bottomRight;

    public Node() {}

    public Node(boolean _val,boolean _isLeaf,Node _topLeft,Node _topRight,Node _bottomLeft,Node _bottomRight) {
        val = _val;
        isLeaf = _isLeaf;
        topLeft = _topLeft;
        topRight = _topRight;
        bottomLeft = _bottomLeft;
        bottomRight = _bottomRight;
    }
};
*/

class Solution {
    public Node intersect(Node quadTree1, Node quadTree2) {
         if (quadTree1.isLeaf){
            // 是否是叶子节点，是的话就返回node1，否则就是node2
             return quadTree1.val ? new Node(true, true, null, null, null, null) : quadTree2;
        }

        if (quadTree2.isLeaf){
            return quadTree2.val ? new Node(true, true, null, null, null, null) : quadTree1;
        }
        Node tl = intersect(quadTree1.topLeft, quadTree2.topLeft), tr = intersect(quadTree1.topRight, quadTree2.topRight),
                bl = intersect(quadTree1.bottomLeft, quadTree2.bottomLeft), br = intersect(quadTree1.bottomRight, quadTree2.bottomRight);
        return tl.isLeaf && tr.isLeaf && bl.isLeaf && br.isLeaf && tl.val == tr.val && tl.val
                == bl.val && tl.val == br.val ?
                new Node(tl.val, true, null, null, null, null) :
                new Node(false, false, tl, tr, bl, br);
    }
}

没看懂题目，所以直接CV了