将非负整数转换为其对应的英文表示。可以保证给定输入小于 231 - 1 。
示例 1:
输入: 123 输出: "One Hundred Twenty Three"
示例 2:
输入: 12345 输出: "Twelve Thousand Three Hundred Forty Five"
示例 3:
输入: 1234567 输出: "One Million Two Hundred Thirty Four Thousand Five Hundred Sixty Seven"
示例 4:
输入: 1234567891 输出: "One Billion Two Hundred Thirty Four Million Five Hundred Sixty Seven Thousand Eight Hundred Ninety One"