public void deepTree(TreeNode node,int deep){
        if(node.left == null && node.right == null){
            minDeep = Math.min(minDeep,deep);
        }
        if(deep >= minDeep)
            return;
        if(node.left != null)
            deepTree(node.left,deep+1);
        if(node.right != null)
            deepTree(node.right,deep+1);
    }