let words = {
  0: "",
  1: "one",
  2: "two",
  3: "three",
  4: "four",
  5: "five",
  6: "six",
  7: "seven",
  8: "eight",
  9: "nine",
  10: "ten",
  11: "eleven",
  12: "twelve",
  13: "thirteen",
  14: "fourteen",
  15: "fifteen",
  16: "sixteen",
  17: "seventeen",
  18: "eighteen",
  19: "nineteen",
  20: "twenty",
  30: "thirty",
  40: "forty",
  50: "fifty",
  60: "sixty",
  70: "seventy",
  80: "eighty",
  90: "ninety"
}

for (let i = 1; i < 10; i++) {
  words[i * 100] = words[i] + " hundred";
}

// 1 -> "one" -> 3
// 10 -> "ten" -> 3
// 19 -> "nineteen" -> 8
// 367 -> "three hundred and sixty seven" -> 5 + 7 + 3 + 5 + 5

// For the numbers 1 - 1000
// sum the total number of characters, excluding spaces
// For numbers > 99 not divisible by 100, an "and" should separate the hundreds from the tens/ones.

function getHundreds(num) {
  if(num < 100) return '';
  return words[Math.floor(num / 100)] + 'hundred';
};

function getTens(num) {
  let restTens = num % 100;
  //  number is one of 100, 200, 300..
  if (restTens === 0) return '';

  if(restTens > 20) {
    let firstPart = words[Math.floor(restTens / 10) * 10];
    let secondPart = words[restTens % 10];
    return firstPart + secondPart;
  }
  // under 20 does not require assembly
  return words[restTens];
}

function getStringLength(num) {
  if(num === 1000) return 'onethousand'.length

  let hundreds = getHundreds(num);
  let tens = getTens(num);

  if(hundreds && tens) {
    console.log(hundreds + "and" + tens);
    return hundreds.length + "and".length + tens.length;
  };
  if(hundreds) {
    console.log(hundreds + tens)
    return tens.length + hundreds.length
  };
  console.log(tens);
  return tens.length;
}

let sum = 0;
for (let n = 1; n < 1000; n++) {
  sum += getStringLength(n);
}
console.log('succes:',sum + 11 === 21124);