Tree DP

Tree form dp It is in the form of binary tree dp, This problem uses an array to save the results of the current node .
res[0] Indicates that the current node is not stolen res[1] Represents the current node

 public int rob(TreeNode root) {
    
        int[] res = recur(root);
        return Math.max(res[0],res[1]);
    }
    public int[] recur(TreeNode root){
    
        int []res = new int[2];
         The current node is empty   return 
        if(root == null) return res;
		 Recursive left and right nodes 
        int[] left = recur(root.left);
        int[] right = recur(root.right);
         Do not steal the current node , You can steal the nodes of left and right children 
        res[0] = Math.max(left[0],left[1]) + Math.max(right[0],right[1]);
         Steal the current node , Then don't steal the left and right child nodes ,[0] Represents that the value of the current node is not stolen 
        res[1] = root.val + left[0] + right[0]; 
        return res;
    }