Facebook Interview Question

applyFilter.js

const items = [
  {type: 'phone', name: 'iPhone', color: 'gold'},
  {type: 'laptop', name: 'Chromebook', color: 'gray'},
];

const excludes = [
  {k: 'color', v: 'gold'},
  {k: 'color', v: 'silver'},
  {k: 'type', v: 'tv'}
];

// O(n * m)
// Before new solution
// excludes.forEach(function(pair) { 
//   items = items.filter((item) => item[pair.k] !== pair.v); 
// });
// return items;

// O(n + m)
function applyFilters(items, excludes) {
  const lookup = excludes.reduce((acc, cur) => {
    const { k, v } = cur;
    if(acc[k]) {
      acc[k][v] = v;
    } else {
      acc[k] = {};
      acc[k][v] = v;
    }
    return acc;
  }, {});

  return items.filter(item => {
    const lookupKeys = Object.keys(lookup);
    const itemKeys = Object.keys(item);
    for(let i = 0; i < lookupKeys.length; i++) {
     let lk = lookupKeys[i];
      if(item.hasOwnProperty(lk) && lookup[lk][item[lk]]) {
        return false;
      }
    }
    return true;
  });
}

const filtered = applyFilters(items, excludes);