验证输入为Laravel 4中的数组

I create dynamic input by using jQuery

<input type="text" name="prices[]" value="1" />
<input type="text" name="prices[]" value="2" />
<input type="text" name="prices[]" value="3" />

I try with this code but It not work.

protected $rules = [
    'title'             => 'required|min:3',
    'state'             => 'required',
    'prices'            => 'required|integer',
    // 'prices[]'            => 'required|integer' // Or
];