Some candies ;)

candies.js

var candies1 = [3, 4, 7, 7, 6, 6]
var candies2 = [5, 1, 12, 12, 12, 5, 6, 8, 8, 5]
var candies3 = [80, 80, 1000000000, 80, 80, 80, 80, 80, 80, 123456789]

var candies = [5, 1, 12, 12, 12, 5, 6, 8, 8, 5]

var typesOfCandies = function(arr) {
  var finalResult = {};
  
  var counting = arr.reduce(function(result, current) {
    result[current] = (result[current] || 0) + 1;
    return result;
  }, {});
  
  finalResult.unique = Object.keys(counting);
  finalResult.number = Object.keys(counting).slice(0, arr.length/2).length;
  
  console.log(finalResult);
  
  return finalResult.number
}

console.log(typesOfCandies(candies1));
console.log(typesOfCandies(candies2));
console.log(typesOfCandies(candies3));