allNonConsecutive.md

Find all non-consecutive numbers

• Your task is to find all the elements of an array that are non consecutive.

• A number is non consecutive if it is not exactly one larger than the previous element in the array. The first element gets a pass and is never considered non consecutive.

• Create a function named allNonConsecutive

• E.g., if we have an array [1,2,3,4,6,7,8,15,16] then 6 and 15 are non-consecutive.

• You should return the results as an array of objects with two values i: <the index of the non-consecutive number> and n: <the non-consecutive number>.

E.g., for the above array the result should be:

[
  { i: 4, n: 6 },
  { i: 7, n: 15 },
];

• If the whole array is consecutive or has one element then return an empty array.

• The array elements will all be numbers. The numbers will also all be unique and in ascending order. The numbers could be positive and/or negetive and the gap could be larger than one.

Solution:

function allNonConsecutive(arr) {
  let res = [];
  for (let i = 0; i < arr.length - 1; i++) {
    if (arr[i + 1] - 1 !== arr[i]) res.push({ i: i + 1, n: arr[i + 1] });
  }
  return res;
}

console.log(allNonConsecutive([1, 2, 3, 4, 6, 7, 8, 10])); // {i: 4, n:6}, {i: 7, n:10}