华为oj 学英语

直接copy别人的感觉他的程序很直观很好理解,具体那位大神的链接忘了，勿怪！

注意事项：

对于什么时候加‘and’请注意！

举个例子 110 ------ one hundred and ten 

101 ------ one hundred and one

1001 ------ one hundred one

#include 
#include 

using namespace std;
string s1[20] = { "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen" };
string s3[10] = { "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety" };

string lessThan100(long num)
{
	string result;
	if (num < 20)
		result = s1[num - 1];
	else if (num <100 && num % 10 == 0)
		result = s3[num / 10 - 2];
	else if (num <100)
		result = s3[num / 10 - 2] + " " + s1[num % 10 - 1];
	return result;
}
string lessThan1000(long num)
{
	string result;
	if (num < 100)
		result = lessThan100(num);
	else if (num % 100 == 0)
		result = s1[num / 100 - 1] + " hundred";
	else
		result = (s1[num / 100 - 1] + " hundred and " + lessThan100(num % 100));
	return result;
}
string lessThanMillion(long num)
{
	string result;
	if (num < 1000)
		result = lessThan1000(num);
	else if (num % 1000 == 0)
		result = lessThan1000(num / 1000) + " thousand";
	else
		result = lessThan1000(num / 1000) + " thousand " + lessThan1000(num % 1000);
	return result;
}
string lessThanBillion(long num)
{
	string result;
	if (num <1000000)
		result = lessThanMillion(num);
	else if (num % 1000000 == 0)
		result = lessThanMillion(num / 1000000) + " million";
	else
		result = lessThanMillion(num / 1000000) + " million " + lessThanMillion(num % 1000000);
	return result;
}
string parse(long num)
{
	string result;
	if (num <= 0 || num >= 10000000000)
		result = "ERROR";
	else if (num < 1000)
		result = lessThan1000(num);
	else if (num < 1000000)
		result = lessThanMillion(num);
	else if (num <1000000000)
		result = lessThanBillion(num);
	else if (num == 1000000000)
		result = "one billion";
	else
		result = s1[num / 1000000000 - 1] + " billion " + lessThanBillion(num % 1000000000);
	return result;
}

int main()
{
	long num = 0;
	cin >> num;
	cout << parse(num);
	return 0;
}

结论 这种分而治之的方法很好用，而且思路很清晰！！！