static int sumSubTree(TreeNode root, int[] sum, TreeNode[] rec) {
		int s=root.val;
		if (root.left!=null)s+=sumSubTree(root.left, sum, rec);
		if (root.right!=null)s+=sumSubTree(root, sum, rec);
		if (s>=sum[0]) rec[0]=root;
		return s;
	}