Your task is to find the first element of an array that is not consecutive.
By not consecutive we mean not exactly 1 larger than the previous element
of the array.
E.g. If we have an array [1,2,3,4,6,7,8] then 1 then 2 then 3 then 4 are
all consecutive but 6 is not, so that's the first non-consecutive number.
If the whole array is consecutive then return null2.
The array will always have at least 2 elements1 and all elements will be
numbers. The numbers will also all be unique and in ascending order. The
numbers could be positive or negative and the first non-consecutive could
be either too!
If you like this Kata, maybe try this one next:
https://www.codewars.com/kata/represent-array-of-numbers-as-ranges
1 Can you write a solution that will return null2 for both [] and [ x ]
though? (This is an empty array and one with a single number and is not
tested for, but you can write your own example test. )
2
Swift, Ruby and Crystal: nil
Haskell: Nothing
Python, Rust, Scala: None
Julia: nothing
Nim: none(int) (See options)
No examples
Solution by -
My Solution
function firstNonConsecutive (arr) {
return arr.reduce((acc, n, i, src) => {
if(n !== src[i-1] + 1 && !acc && i !=0) return n;
return acc;
}, null);
}
Your task is to find the first element of an array that is not consecutive.
By not consecutive we mean not exactly 1 larger than the previous element
of the array.
E.g. If we have an array [1,2,3,4,6,7,8] then 1 then 2 then 3 then 4 are
all consecutive but 6 is not, so that's the first non-consecutive number.
If the whole array is consecutive then return null2.
The array will always have at least 2 elements1 and all elements will be
numbers. The numbers will also all be unique and in ascending order. The
numbers could be positive or negative and the first non-consecutive could
be either too!
If you like this Kata, maybe try this one next:
https://www.codewars.com/kata/represent-array-of-numbers-as-ranges
1 Can you write a solution that will return null2 for both [] and [ x ]
though? (This is an empty array and one with a single number and is not
tested for, but you can write your own example test. )
2
Swift, Ruby and Crystal: nil
Haskell: Nothing
Python, Rust, Scala: None
Julia: nothing
Nim: none(int) (See options)
No examples
Solution by -
My Solution
function firstNonConsecutive (arr) {
return arr.reduce((acc, n, i, src) => {
if(n !== src[i-1] + 1 && !acc && i !=0) return n;
return acc;
}, null);
}
