Vending machine DFA transitions

vending.js

// usage: node vending.js > transitions
var coins = [5, 10, 25, 100];
var _sum = 125;

var validTransitions = [];
coins.forEach(function (c) { check(0, c); })

function check(sum, coin, transitions) {
  transitions = transitions || [];
  var newSum = sum + coin;
  var symbol;
  switch (coin) {
    case 5: symbol = 'nickel'; break;
    case 10: symbol = 'dime'; break;
    case 25: symbol = 'quarter'; break;
    case 100: symbol = 'loonie'; break;
  }
  if (newSum < _sum) {
    transitions.push(sum + ' ' + symbol + ' ' + newSum);
    coins.forEach(function (coin) {
      check(newSum, coin, copy(transitions))
    });
  } else if (newSum === _sum) {
    transitions.push(sum + ' ' + symbol + ' ' + newSum);
    validTransitions.push(transitions);
  }
}

console.error(validTransitions.length);

var uniqueTransitions = {};
validTransitions.forEach(function (transitions) {
  transitions.forEach(function (t) {
    if (!uniqueTransitions[t]) {
      uniqueTransitions[t] = 1;
    }
  });
});

// output valid states
var i = 0;
console.log(26);
while (i != 130) { console.log(i); i += 5;}

// output all transitions
console.log(Object.keys(uniqueTransitions).length);
Object.keys(uniqueTransitions).forEach(function (t) {
  console.log(t);
});

function copy(array) {
  var c = [], len = array.length, i = 0;
  while (i < len) {
    c.push(array[i]);
    i += 1;
  }
  return c;
}