Facebook Interview - Integer to English Phrase - 我的博客 - ITeye技术网站

Facebook Interview - Integer to English Phrase - 我的博客 - ITeye技术网站
Given an integer between 0 and 999,999, print an English phrase that describes the integer (eg, "One Thousand, Two Hundred and Thirty Four")

1. vector<string> under20 = {"Zero", "One", "Two", "Three", "Four", "Five",   
2.         "Six", "Seven", "Eight", "Nine", "Ten",  
3.         "Eleven","Twelve", "Thirteen", "Fourteen", "Fifteen",  
4.         "Sixteen", "Seventeen", "Eighteen", "Nineteen", "Twenty"};  
5.    
6. vector<string> tens = {"Zero", "Ten", "Twenty", "Thirty", "Forty", "Fifty",   
7.         "Sixty", "Seventy", "Eighty", "Ninety"};  
8.   
9. string numBelow1000(int num) {  
10.     if(num == 0) return under20[0];  
11.     string ret = "";  
12.     if (num > 100) {  
13.         ret = under20[num/100] + " Hundred";  
14.         num %= 100;  
15.         if (num == 0) {  
16.             return ret;  
17.         } else {  
18.             ret += " and ";  
19.         }   
20.     }  
21.       
22.     if (num <= 20) {  
23.         ret += under20[num];  
24.     } else {  
25.         ret += tens[num/10];  
26.         num %= 10;  
27.         if (num > 0)  
28.             ret += " " + under20[num];  
29.     }  
30.     return ret;  
31. }  
32. string num2string(int num) {  
33.     int part1 = num / 1000;  
34.     int part2 = num % 1000;  
35.     string res;  
36.     if(part1) {  
37.         res = numBelow1000(part1) + " Thousand";  
38.         if(part2) res += ", " + numBelow1000(part2);  
39.     } else {  
40.         res = numBelow1000(part2);  
41.     }  
42.     return res;  
43. } 

http://www.source-code.biz/snippets/java/13.htm
http://www.dzone.com/snippets/convert-integer-english-0

https://github.com/wuyanna/DataStructureAndAlgorithm_JAVA/blob/master/src/com/question/moderate/IntegerEnglish.java

Given any integer, print an English phrase that describes the integer (e.g., "One Thousand, Two Hundred Thirty Four").

String[] smalls = {"Zero", "One", "Two", "Three", "Four", "Five", "Six", "Seven",
                   "Eight", "Nine", "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen",
                   "Sixteen", "Seventeen", "Eighteen", "Nineteen"};
String[] tens ={"", "", "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy",
                "Eighty", "Ninety"};
String[] bigs ={"", "Thousand", "Million", "Billion"};
String hundred= "Hundred";
String negative = "Negative";

String convert(int num) {
        if (num == 0) {
                return smalls[0];
        } else if (num < 0) {
                return negative + " " + convert( -1 * num);
        }
        Linkedlist<String> parts =  new Linkedlist<String>();
        int chunkCount = 0;
        while (num > 0) {
                if (num % 1000 != 0) {
                        String chunk= convertChunk(num % 1000) + " " + bigs[chunkCount];
                        parts.addFirst(chunk);
                }
                num /= 1000; // shift chunk
                chunkCount++;
        }

        return listToString(parts);
}

String convertChunk(int number) {
        Linkedlist<String> parts = new Linkedlist<String>();

        /* Convert hundreds place */
        if (number>= 100) {
                parts.addlast(smalls[number / 100]);
                parts.addLast(hundred);
                number%= 100;
        }

        /* Convert tens place */
        if (number >= 10 && number <= 19) {
                parts.addlast(smalls[number]);
        } else if (number >= 20) {
                parts.addlast(tens[number / 10]);
                number%= 10;
        }

        /* Convert ones place */
        if (number >= 1 && number <= 9) {
                parts.addlast(smalls[number]);
        }

        return listToString(parts);
}
/* Convert a linked list of strings to a string, dividing it up with spaces. */
String listToString(LinkedList<String> parts) {
        StringBuilder sb = new StringBuilder();
        while (parts.size() > 1) {
                sb.append(parts.pop());
                sb.append(" ");
        }
        sb.append(parts.pop());
        return sb.toString();
}
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