输入12345，输出 一万二千三百四十五，考虑到亿

// 输入： 12345 输出：一万二千三百四十五

function test(num) {
    let numbers = ['零', '一', '二', '三', '四', '五', '六', '七', '八', '九']
    let units = ['', '十', '百', '千']
    let units2 = ['', '万', '亿', '兆', '京']
    let res = ''
    let loop = 0
    while (num) {
        let count = 0
        let part = num % 10000
        let partStr = ''
        while (part) {
            let unit = units[count]
            let i = part % 10
            let numberStr = numbers[i]
            partStr = `${numberStr}${unit}${partStr}`
            part = Math.floor(part / 10)
            count++
        }
        res = partStr + units2[loop] + res
        num = Math.floor(num / 10000)
        loop++
        count = 0
    }
    return res
}