minimum_number_of_stamps_1.js

var minimum_number_of_stamps = function() {
  var memo = [];
  var min_stamps = function(postage, stamps) {
    if (postage == 0) {
      return 0;
    } else if (memo[postage]) {
      return memo[postage];
    } else {
      var min = postage;
      for (var i = 0; i < stamps.length; i++) {
        if (stamps[i] <= min) {
          number = 1 + min_stamps(postage - stamps[i], stamps);
          if (number < min) {
            min = number;
          }
        }
      }
    }
    memo[postage] = min;
    return min;
  };
  return min_stamps;
}();