interview questions

remove_dupes.js

function dedupe(list = []) {
  let dedupes = [];
  let dupes = [];
  let i = list.length;

  while (i-- > 0) {
    let item = list[i];
    // first time
    if (dedupes.indexOf(item) === -1) {
      dedupes.unshift(item);

    // 2nd time
    } else if (dupes.indexOf(item) === -1) {
      dupes.unshift(item);
    } 
  }

  return {
    dedupes: dedupes,
    dupes: dupes
  };
}