Groupon面试题

看到今天别人发的groupon的面经，有一道题是这样的，请问该怎么解？nt3acres.com/bbs
write a function
f(4) = four
f(14) = fourteen
f(123) = one hundred, twenty three
f(12345) = twelve thousand, three hundred, forty five

抛砖： 假设input 是 String input = “123456”。根据input.length()/3 的 结果来决定 当前单位是多少，如果input.length()/3 == 1 且input.length() % 3>0.则单位是千，然后百万，十亿。 先处理 input.length() % 3,然后三个 三个的 读。

public class Solution {
        public String f(int n) {
                if (n == 0) return "zero";
                boolean pos = n > 0;
                long num = n;
                if (num < 0) num = -num;
                String[] a1 = new String[] {"", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"};
                String[] a2 = new String[] {"", "", "twenty", "thirty", "fourty", "fifty", "sixty", "seventy", "eighty", "ninety"};
                String[] base = new String[] {"", "thousand", "million", "billion"};
                int b = 0;
                int d = 1;
                while (num/d >= 1000) {
                        b++;
                        d *= 1000;
                }
                StringBuilder sb = new StringBuilder();
                while (b >= 0) {
                        int v = (int)(num/d);
                        if (v >= 100) {
                                sb.append(a1[v/100]+" hundred ");
                                v %= 100;
                        }
                        if (v < 20) {
                                sb.append(a1[v]);
                        } else {
                                sb.append(a2[v/10]+" "+a1[v%10]);
                        }
                        sb.append(" "+base[b]+" ");
                        b--;
                        num %= d;
                        d /= 1000;
                }
                String ret = sb.toString().trim();
                return pos ? ret : "minus "+ret;
        }
}

Test:

4 four
14 fourteen
123 one hundred twenty three
12345 twelve thousand three hundred fourty five
1000 one thousand
100 one hundred
10 ten
1 one
0 zero
2147483647 two billion one hundred fourty seven million four hundred eighty three thousand six hundred fourty seven
-2147483648 minus two billion one hundred fourty seven million four hundred eighty three thousand six hundred fourty eight

Leet Code 273. Integer to English Words

多谢啊，看来还是刷题不够啊

楼主你好，YouTube上有个大神讲解LeetCode的题目的，这里是这道题的视频链接：https://www.youtube.com/watch?v=RwFQvF0xx_k&list=PLvyIyKZVcfAmc54SmSOw0E6Y6L9oReTeb&index=23