273. 整数转换英文表示

题目链接：273. 整数转换英文表示 - 力扣（LeetCode）

 

 

 

 

 

 

 

 

 

 

 

解析：

中文转英文：每三位一组，先用英文表示，然后从第二组开始向后几组分别增加单位

"Thousand", "Million", "Billion"

比如101001

"One Hundred One Thousand One"

 

class Solution {
public:vector<string> singles = {"", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine"};vector<string> teens = {"Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen"};vector<string> tens = {"", "Ten", "Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety"};vector<string> thousands = {"", "Thousand", "Million", "Billion"};string get_english(int temp) {string ret = "";int a = temp / 100;if (a > 0) {ret = singles[a] + " Hundred";}temp -= a * 100;if (temp == 0) return ret;else if (temp < 20) {if (ret != "") ret += " ";if (temp < 10) ret += singles[temp];else ret += teens[temp - 10];} else {if (ret != "") ret += " ";int b = temp / 10;ret += tens[b];temp -= b * 10;if (temp == 0) return ret;ret += " ";ret += singles[temp];return ret;}return ret;}string numberToWords(int num) {if (num == 0) return "Zero";string ret = "";int cnt = 0;while(num) {int temp = num % 1000;string temp_str = get_english(temp);            if (temp_str != "" && thousands[cnt] != "") temp_str += " " + thousands[cnt];if (ret != "" && temp_str != "") temp_str += " "; ret = temp_str + ret;cnt++;num /= 1000;}return ret;}
};