length-of-missing-array.js

// kata https://www.codewars.com/kata/57b6f5aadb5b3d0ae3000611

// Input - Array of arrays
// Output - Length of missing array
// [[1, 2], [4, 5, 1, 1], [1], [5, 6, 7, 8, 9]] --> 3

function getLengthOfMissingArray(arr) {
  const lengths = (arr || []).map((a) => (a ? a.length : 0)).sort((a, b) => a - b);
  if (lengths.some((x) => x === 0)) return 0;
  for (let i = 0; i < lengths.length - 1; i++) {
    if (lengths[i] + 1 !== lengths[i + 1]) {
      return lengths[i] + 1;
    }
  }
  return 0;
}

console.log(getLengthOfMissingArray([[], [4], [4, 1, 3, 0], [0, 3, 0, 3, 0], [2, 2], [0, 0, 1, 1, 4, 4], [0, 4, 1, 1, 3, 0, 4]]), 0);
// console.log(getLengthOfMissingArray([[1, 2], [4, 5, 1, 1], [1], [5, 6, 7, 8, 9]]), 3);
// console.log(getLengthOfMissingArray([[5, 2, 9], [4, 5, 1, 1], [1], [5, 6, 7, 8, 9]]), 2);
// console.log(getLengthOfMissingArray([[null], [null, null, null]]), 2);
// console.log(getLengthOfMissingArray([['a', 'a', 'a'], ['a', 'a'], ['a', 'a', 'a', 'a'], ['a'], ['a', 'a', 'a', 'a', 'a', 'a']]), 5);
// console.log(
//   getLengthOfMissingArray([
//     [0, 1, 4],
//     [0, 0, 0, 4, 0],
//     [4, 3, 2, 0, 1, 4, 4],
//     [0, 2, 3, 0, 1, 3, 4, 0, 2],
//     [0, 2, 2, 2],
//     [0, 4, 0, 0, 3, 2, 3, 4],
//     [4, 1, 2, 0, 2, 4, 0, 0, 0, 0, 4],
//     [2, 4, 3, 3, 2, 4, 4, 2, 3, 1],
//   ]),
//   6
// );