If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total.

If all the numbers from 1 to 1000 (one thousand) inclusive were written out in words, how many letters would be used?

NOTE: Do not count spaces or hyphens. For example, 342 (three hundred and forty-two) contains 23 letters and 115 (one hundred and fifteen) contains 20 letters. The use of "and" when writing out numbers is in compliance with British usage.

Solution:

If all the numbers from 1 to 1000 (one thousand) inclusive were written out in words, how many letters would be used?

NOTE: Do not count spaces or hyphens. For example, 342 (three hundred and forty-two) contains 23 letters and 115 (one hundred and fifteen) contains 20 letters. The use of "and" when writing out numbers is in compliance with British usage.

Solution:

void Solution() { Dictionary<int, string> numbers = new Dictionary<int, string>(); numbers.Add(1, "one"); numbers.Add(2, "two"); numbers.Add(3, "three"); numbers.Add(4, "four"); numbers.Add(5, "five"); numbers.Add(6, "six"); numbers.Add(7, "seven"); numbers.Add(8, "eight"); numbers.Add(9, "nine"); numbers.Add(10, "ten"); numbers.Add(11, "eleven"); numbers.Add(12, "twelve"); numbers.Add(13, "thirteen"); numbers.Add(14, "fourteen"); numbers.Add(15, "fifteen"); numbers.Add(16, "sixteen"); numbers.Add(17, "seventeen"); numbers.Add(18, "eighteen"); numbers.Add(19, "nineteen"); numbers.Add(20, "twenty"); numbers.Add(30, "thirty"); numbers.Add(40, "forty"); numbers.Add(50, "fifty"); numbers.Add(60, "sixty"); numbers.Add(70, "seventy"); numbers.Add(80, "eighty"); numbers.Add(90, "ninety"); numbers.Add(100, "hundred"); numbers.Add(1000, "thousand"); int sum = 0; for (int i = 1; i <= 20; i++) { sum += numbers[i].Length; Console.WriteLine(numbers[i] + " " + numbers[i].Length); } for (int i = 21; i < 100; i++) { int key = i / 10; if (i % 10 != 0) sum += numbers[key * 10].Length + numbers[i % 10].Length; else sum += numbers[key * 10].Length; } int sumTill1To99 = sum; for (int i = 101; i < 999; i = i + 100) { int key = i / 100; sum += numbers[key].Length + numbers[100].Length; sum += (numbers[key].Length + numbers[100].Length + "and".Length) * 99; sum = sum + sumTill1To99; } sum = sum + numbers[1].Length + numbers[1000].Length; }