aoc-4-1.js

var fs = require('fs');
var text = fs.readFileSync('input.txt', 'utf8');
var data = text.split('\n');

function isValid(password) {
  var parts = password.split(' ');
  var isValid = true;
  var hash = {};
  
  for (var i = 0; i < parts.length; i++) {
    var part = parts[i];
    
    if (hash[part] && hash[part] === 1) {
        isValid = false;
        break;
    } else {
      hash[part] = hash[part] ? (hash[part] + 1) : 1;
    } 
  };
  
  return isValid;
}

function checkArray(data) {
    return data.reduce(function (acc, item) {
        return acc + isValid(item);
    }, 0);
}

console.log(checkArray(data));

aoc-4-2.js

var fs = require('fs');
var text = fs.readFileSync('input.txt', 'utf8');
var data = text.split('\n');

function isValid(password) {
  var parts = password.split(' ');
  var isValid = true;
  var hash = {};
  
  for (var i = 0; i < parts.length; i++) {
    var part = parts[i].split('').sort().join('');
    
    if (hash[part] && hash[part] === 1) {
        isValid = false;
        break;
    } else {
      hash[part] = hash[part] ? (hash[part] + 1) : 1;
    } 
  };
  
  return isValid;
}

function checkArray(data) {
    return data.reduce(function (acc, item) {
        return acc + isValid(item);
    }, 0);
}

console.log(checkArray(data));