Contiguous array with the same degree

contiguous-array-with-the-same-degree.js

function alg(arr) {
  const maxFreqNum = findMaxFreqNum(arr)

  const firstIndex = arr.indexOf(maxFreqNum)
  const lastIndex = arr.lastIndexOf(maxFreqNum)

  const contiguousArr = arr.slice(firstIndex, lastIndex+1)
  return contiguousArr.length
}

function findMaxFreqNum(arr) {
  const nums = {};
  arr.forEach(el => {
    if(!(el in nums)) {
      nums[el] = 0
    }
    nums[el] += 1
  })

  let maxFreqNum = -1;
  let maxFreq = -1;
  
  Object.entries(nums).forEach(([n, freq]) => {
    if(freq > maxFreq) {
      maxFreq = freq
      maxFreqNum = n
    }
  })

  return +maxFreqNum // Keys of Objects are Strings, converting to Number
}

function parseInput(data) {
  const [lengthStr, arrayStr] = data.split('\n')
  const array = arrayStr.split(' ').map(n => parseInt(n, 10))
  return array
}

// Testing
console.log(alg([1,2,5,6,1]))
console.log(alg([1,1,1,2,3]))
console.log(alg([1,2,3,4,4,4,5,6]))
console.log(alg([1,2,3,4,4,0,0,4,5,6]))