dice thing

dice.js

var Dice = {
  B: [0, 0, 0, 0, 1, 1],
  A: [0, 0, 0, 0, 1, 1, 1, 2],
  P: [0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2],
  S: [0, 0, 0, 0, -1, -1],
  D: [0, 0, 0, 0, 0, -1, -1, -2],
  C: [0, 0, 0, 0, 0, -1, -1, -1, -1, -1, -2, -2]
};

function applyToEach (set, func) {
  for (var item in set) {
    if (set.hasOwnProperty(item)) {
      func(item);
    }
  }
}

function mapProbability (die) {
  var prob = {};

  applyToEach(die, function (i) {
    if (prob[die[i]] == null) {
      prob[die[i]] = 0;
    }

    prob[die[i]]++;
  });

  return prob;
}

function addProbability (setA, setB) {
  var result = {};

  applyToEach(setA, function (ia) {
    applyToEach(setB, function (ib) {
      if (result[~~ia + ~~ib] == null) {
        result[~~ia + ~~ib] = 0;
      }

      result[~~ia + ~~ib] += setA[ia] * setB[ib];
    });
  });

  return result;
}

function buildProbability (diceString) {
  var probability = mapProbability(Dice[diceString[0]]);

  for (var i = 1; i < diceString.length; ++i) {
    probability = addProbability(probability, mapProbability(Dice[diceString[i]]));
  }

  return probability;
}

function calcProbability (set, test) {
  var frequency = 0;
  var total = 0;

  applyToEach(set, function (i) {
    total += set[i];

    if (test(i)) {
      frequency += set[i];
    }
  });

  return (frequency / total) * 100;
}

function success (input) {
  return calcProbability(buildProbability(input), function (i) {
    return (~~i) > 0;
  });
}