i’m trying to create a function that gives me an array of numbers with a limitation of repetition for each number. for example

([1,1,3,3,7,2,2,2,2], 3)

should give me

[1, 1, 3, 3, 7, 2, 2, 2]

it deletes a [2] because the max repetition of numbers is 3.

here is my code but i don’t know why it doesn’t work:

function deleteNth(arr,n){ var results = []; for(var i=0; i<arr.length; i++){ if (count(results, arr[i])<=n) { results.push(arr[i]); } } return results; } function count(array, what){ var count =0; for (var i=0; i<array.length; i++){ if (array[i]===what){ count++; } } return count; } console.log(deleteNth([1,1,3,3,7,2,2,2,2], 3));

## Answer

I would use a `reduce`

to iterate over all elements of the array and a dictionary to keep track of the number of times I found an element.

Here’s an example:

const filterReps = (arr, maxReps) => { return arr.length ? arr.reduce((acc, num, i) => { // Add this number to our dictionary, // if already present add +1 to it's count acc.found[num] = acc.found[num] ? ++acc.found[num] : 1 // If the dictionary says the number has been found less or equal // times to our max repetitions, push it into the accumulating array if (acc.found[num] <= maxReps) acc.arr.push(num) // If this is the final iteration, just return only the result array // and not the dictionary return i === nums.length - 1 ? acc.arr : acc }, { found: {}, arr: [] }) : arr } const nums = [1, 1, 1, 1, 2, 2, 2, 2] console.log(filterReps(nums, 3))