code-challenge.js

const input = [
  9, 44, 32, 12, 7, 45, 31, 98, 35, 41, 8, 20, 27, 32, 83, 64, 61, 28, 39, 93,
  29, 92, 17,
];

function solution(arr) {
  const length = arr.length;
  if (!length) return { sequence: [], removed: 0 };

  const longest = new Array(length).fill(1);
  const previous = new Array(length).fill(-1);

  for (let i = 1; i < length; i++) {
    for (let j = 0; j < i; j++) {
      if (arr[j] < arr[i] && longest[j] + 1 > longest[i]) {
        longest[i] = longest[j] + 1;
        previous[i] = j;
      }
    }
  }

  let maxLength = 0;
  let maxIndex = 0;

  for (let i = 0; i < length; i++) {
    if (longest[i] > maxLength) {
      maxLength = longest[i];
      maxIndex = i;
    }
  }

  // Here we already know what is the amount of removed elements: length - maxLength
  const removed = length - maxLength;

  const sequence = [];
  let currIndex = maxIndex;
  while (currIndex !== -1) {
    sequence.unshift(arr[currIndex]);
    currIndex = previous[currIndex];
  }

  return { sequence, removed };
}

const result = solution(input);
console.log(result);