Project Euler - Problem 17

euler.java

package euler;

public class NumWords {
	public static void main(String[] args) {
		
		StringBuilder sb = new StringBuilder();
		for (int i = 1; i <= 1000; i++) {
			sb.append(numToWord(i));
		}
		System.out.println(sb.toString().length());
	}

	public static String numToWord(int num) {
		if (num == 0) return "zero";
		else if (num == 1) return "one";
		else if (num == 2) return "two";
		else if (num == 3) return "three";
		else if (num == 4) return "four";
		else if (num == 5) return "five";
		else if (num == 6) return "six";
		else if (num == 7) return "seven";
		else if (num == 8) return "eight";
		else if (num == 9) return "nine";
		else if (num == 10) return "ten";
		else if (num == 11) return "eleven";
		else if (num == 12) return "twelve";
		else if (num == 13) return "thirteen";
		else if (num == 14) return "fourteen";
		else if (num == 15) return "fifteen";
		else if (num == 16) return "sixteen";
		else if (num == 17) return "seventeen";
		else if (num == 18) return "eighteen";
		else if (num == 19) return "nineteen";
		else if (num == 20) return "twenty";
		else if (num == 30) return "thirty";
		else if (num == 40) return "forty";
		else if (num == 50) return "fifty";
		else if (num == 60) return "sixty";
		else if (num == 70) return "seventy";
		else if (num == 80) return "eighty";
		else if (num == 90) return "ninety";
		else if (num == 1000) return "onethousand";
		else if (num > 20 && num < 100)
			return numToWord(num / 10 * 10) + numToWord(num - num / 10 * 10);
		else if (num % 100 == 0)
			return numToWord(num / 100) + "hundred";
		else if (num > 100 && num < 1000)
			return numToWord(num / 100 * 100) + "and" + numToWord(num - num / 100 * 100);
		else return "unknown";
	}
}