看到某团招聘信息有这样一段：

有资格进入我们面试的人(以下试题如果不会做就不要投简历了)【整数数字转读音】string num2Voice(int num){...}例：输入：12345 输出：一万二千三百四十五(时间20min内完成代码并能够跑通)

感觉这题练手挺好，所以试了试。非常惭愧，20min确实搞不定。最终搞了n个20min，才能跑完自己的所有测试用例。我用的测试用例如下：

@Test	public  void runTest() {		Assert.assertEquals("零", num2Voice(0));		Assert.assertEquals("负二十一亿四千七百四十八万三千六百四十八", num2Voice(-2147483648));		Assert.assertEquals("二十一亿四千七百四十八万三千六百四十七", num2Voice(2147483647));		Assert.assertEquals("一十", num2Voice(10));		Assert.assertEquals("八", num2Voice(8));		Assert.assertEquals("负八", num2Voice(-8));		Assert.assertEquals("九十九", num2Voice(99));		Assert.assertEquals("一百", num2Voice(100));		Assert.assertEquals("一百零一", num2Voice(101));		Assert.assertEquals("九百九十九", num2Voice(999));		Assert.assertEquals("一千", num2Voice(1000));		Assert.assertEquals("一千零一", num2Voice(1001));		Assert.assertEquals("一千零一十", num2Voice(1010));		Assert.assertEquals("一千一百", num2Voice(1100));		Assert.assertEquals("一万", num2Voice(10000));		Assert.assertEquals("一十万",num2Voice(100000));		Assert.assertEquals("一百万", num2Voice(1000000));		Assert.assertEquals("一千万", num2Voice(10000000));		Assert.assertEquals("一亿", num2Voice(100000000));		Assert.assertEquals("一十亿", num2Voice(1000000000));		Assert.assertEquals("一十亿零一",  num2Voice(1000000001));		Assert.assertEquals("一十亿零一十",  num2Voice(1000000010));		Assert.assertEquals("一十亿零一万", num2Voice(1000010000));		Assert.assertEquals("一十亿零一万零一十", num2Voice(1000010010));		Assert.assertEquals("一十亿零一千零一十万零一千零一十", num2Voice(1010101010));		Assert.assertEquals("一十九亿九千九百九十九万九千九百九十九", num2Voice(1999999999));	}

以下是分析过程：

1. 根据题目给出的函数原型，知道要转的是java int数据。int取值范围：-2147483648至2147483647，所以数位最多到十亿位。int值有正有负，读法是负数前加“负”

2. 数位中个位的个，按习惯是不读出的。

3. 数位中若连续有多个零，只读一个零。且最低位连续的多个零不用读。

4. 数位中万位至千万位中若全部为零，不用加万字，否则加万字。

代码如下(待优化)：

private static char[] digit_cn = "零一二三四五六七八九十".toCharArray();	private static char[] numerical_digit_cn = "个十百千万十百千亿十".toCharArray();			private static String INTEGER_MAX_VOICE_CN = "二十一亿四千七百四十八万三千六百四十七";	private static String INTEGER_MIN_VOICE_CN = "负二十一亿四千七百四十八万三千六百四十八";	private static String INTEGER_ZERO_VOICE_CN = "零";	public static String num2Voice(int num) {		// 几个特殊值的处理		if (num == 0)	return INTEGER_ZERO_VOICE_CN;		if (num == Integer.MAX_VALUE) return INTEGER_MAX_VOICE_CN;		if (num == Integer.MIN_VALUE) return INTEGER_MIN_VOICE_CN;		StringBuffer sb = new StringBuffer();		boolean isNegative = false;		// 负值转正值，统一处理		if (num < 0) {			num = -num;			isNegative = true;		}		// 绝对值小于9的数字简化处理		if (num < 10) {			sb.append(digit_cn[num]);		} else {			int numerical_index = 0; // 指示当前数位			boolean isNeedRemoveWan = true;			boolean isContinuesZero = false; // 是否是连续的多个零的标志位			while (num >= 10) {				int n = num % 10;				if (n != 0) {					sb.append(numerical_digit_cn[numerical_index]);					sb.append(digit_cn[n]);					isContinuesZero = false;						if (numerical_index >= 4 && numerical_index <8) {						isNeedRemoveWan = false;					}				} else {					if (!isContinuesZero) {						sb.append(digit_cn[n]);						isContinuesZero = true;					}										if (numerical_index == 8 && isNeedRemoveWan) {						sb.deleteCharAt(sb.length() -1);					}					if (numerical_index == 4 || numerical_index == 8) {						sb.append(numerical_digit_cn[numerical_index]);					}									}				num = num / 10;				numerical_index++;			}						if (numerical_index == 8 && isNeedRemoveWan) {				sb.deleteCharAt(sb.length() -1);			}						sb.append(numerical_digit_cn[numerical_index]);			sb.append(digit_cn[num]);			sb.deleteCharAt(0);// 个位是0时会填“零”，个位不为0时会填“个”，按习惯这个都不读出来		}		if (isNegative){			sb.append("负");                }		return sb.reverse().toString().trim();	}