Voting Exercise

voting-exercise.js

var fs = require('fs');
var readline = require('readline');
var stream = require('stream');

var instream = fs.createReadStream('votes.txt');
var outstream = new stream;
var rl = readline.createInterface(instream, outstream);

var ballotCount = 0;
var ballotVotes = [];
var ballotCounts = {};

function incrementBallotCountForKey(key) {
  if (ballotCounts[key] === undefined) {
    ballotCounts[key] = 1;
  } else {
    ballotCounts[key]++;
  }
}

function addCountsForBallot(ballotVotes) {
  let key1 = ballotVotes[0] + '-over-' + ballotVotes[1];
  incrementBallotCountForKey(key1);
  let key2 = ballotVotes[0] + '-over-' + ballotVotes[2];
  incrementBallotCountForKey(key2);
  let key3 = ballotVotes[1] + '-over-' + ballotVotes[2];
  incrementBallotCountForKey(key3);
}

rl.on('line', function(line) {
  if (ballotCount == 3) {
    addCountsForBallot(ballotVotes);
    // console.log(ballotVotes.join(',')); // part # 2
    ballotVotes = [];
    ballotCount = 0;
  }

  var candidateId = line.substring(37, 43);
  ballotVotes[ballotCount] = candidateId;
  ballotCount++;
});

rl.on('close', function() {
  console.log(ballotCounts);
});