Consolidate to survive

There are rumors of newly spun Nokia-Siemens Networks (NSN) taking over Tellabs in an effort to garner share in the optical and FTTN/FTTH markets in the US. This might make sense as both have complementary product strategies and common European roots. The lone vendor standing out in the crowd seems to be Juniper. Let’s watch and see what happens to Juniper in the long run!

Sun CTO Greg Papadopoulos articulates on his blog that the world needs only 5 computers(Google, Microsoft, Yahoo, Amazon, eBay and Salesforce. That’s O(5) according to him!). Similarly, with the consolidations happening in the networking industry, I feel the world needs only 5 equipment vendors: Cisco, Ericsson, Nokia Siemens Networks, Huawei, Motorola/Qualcomm and Alcatel-Lucent. That's O(5) according to me!).

SunRockets demise

SunRocket, providers of VOIP services recently announced their bankruptcy. Thousands of SunRocket’s subscribers were left in a lurch with no telephone service. Today, the telephone is a basic service essential for customers: individual subscribers, small business owners or college students. This spectrum of subscribers in most cases draw their livelihood using a telephone. These cost-sensitive subscribers get easily wooed to low-cost VOIP services provided by “startup” providers. But how do subscribers protect themselves in situations like these? SunRocket had no transition plan for their customers and all they were left with was with a notice on their website. On account of the subscribers, the following should be addressed.

• FCC not having a policy to protect subscribers in cases like these
• VC firms backing up companies providing essential services should be held responsible. Mayfield Ventures which backed SunRocket has conveniently sidelined itself! Lack of business planning was one of the major reasons for their demise
• There should be minimum capital with the company at all times to accommodate these situations
• There should be clear directives to these companies to transition subscribers to another provider in case of a failure

Do you want your essential services managed and operated by a “startup”? I am not sure. Imagine you entrust your electricity services or your heart pacemaker in the hands of a “startup”? Would you do that?

That raises the other important question. Does this mean we are at the disposal of the big traditional cable and telephone companies? With the plethora of consolidations happening in the market place, I feel we do. This is a classic example of how difficult it is to be a pure-play VOIP provider in a quad-play world. It’s going to be a tough business for providers like these and these companies need to get some tips from “Swim with the sharks without being eaten alive” to stay afloat and be profitable.

Interesting puzzle II

First, consider a function P(x) where:

  P(x) returns:
   true if the number of 1 bits set in the
     binary representation of x is prime,

   false otherwise.

For example, P(239) returns true, while P(51) returns false.

Next, consider the following function prime_bits:

  uint64_t prime_bits(uint64_t a, uint64_t b);

A call to prime_bits(a, b) returns the number of values between a and b inclusive for which P(x) is true. For example, prime_bits(4, 10) returns 5, while prime_bits(137, 31415926535897) returns 7753256197126. Your job is to implement the prime_bits function.

Your implementation should be efficient, and it should be wrapped up nicely such that one can specify a and b on the commandline when running your program. You may expect the range of a and b to be limited to non-negative 64-bit integers, though it would certainly be uncouth for your algorithm to break down for larger values.

Your implementation should have a running time faster than O(n), where n is b - a.

Interesting puzzle I

There are 9 casinos, laid out in the following configuration, with the lines between them representing overnight travel routes:

1 ---- 2 ---- 3
|      |      |
|      |      |
4 ---- 5 ---- 6
|      |      |
|      |      |
7 ---- 8 ---- 9

On an otherwise uneventful visit to one of these casinos, your dear mother has had the misfortune to be enslaved by an evil gambling monster. I call him Gamblor, and it is time to snatch her away from his neon claws.^[1]

Unfortunately, Gamblor demands the payment of a great deal of money in return for releasing his hostage.

Luckily, you are a psychic computer scientist. With your powers, you can predict in advance over the next 30 days how much you would win (or lose) if you played at a particular casino on that day. This schedule of winnings is represented by the following nine 30-element arrays:

wins1 = [ 53,-84, 50,-73, 54, 60, 74, 22,-63,-78, 75, 72,
        -46, 99,-33, 24,  6,-66, 77,-61,-60,-46,-52, 84,
         91,-21,-52,-72,-39,-41]
wins2 = [ 77,-86,-25, 27,-59,-71,-13,-85, 50, 24,-63, 26,
         -4,-10, 25, 62,-85,-68, 96, 92,-29,-64,-54, 18,
        -79,-62, 97,-32,-35,-42]
wins3 = [ 27,-57,-28,-98, 69, 12,-70,-43, 27, 80, 80, 64,
          6,-23,-45,-68,-60,-31,-36,-63,-39, 34,-27,  7,
        -47, -7, 44,-50, 60,-90]
wins4 = [  7,-12,-48, 79,-11,-78, -8, 19,-21,-81, -1,-40,
         83,-95, 36,-62,-63, 76,  6,  0,-87, 67,-66,-15,
        -26,-14, 78,-81, 36, 38]
wins5 = [-71,-56,-73,-20,-77, 15,  2, 14,-66, 81, 33, 33,
        -59, 16, 37, 77, 53, 73, 53,-40,-26, 66,-73,  7,
        -48,  1, 93,-70, 19, 30]
wins6 = [ 68, 47, 73, 94,-72, 96, 10, 30, 11, 44, 11,-56,
        -23, 51, 60,-86, 29, 13, 87,-17, 73,-39,-51,-99,
         68,  1,  1, 62, 30,-79]
wins7 = [ -8, -1, 68,-34, -7, 96,-37,-96, 26, 73, 47,-62,
        -83,-76, 89, 77,-62, 18, -9,-75,-99,-36,-14,-50,
        -36,-45, 50, 64,-83,-19]
wins8 = [ 85,  9, 79, 53, 75,-28, 49,-62,-25,-24,-89,-77,
         13,-72,-54,  2,-95,-17,-80, -5,  8,-79, 59, 93,
        -30,-77,-51,-79, 87,-35]
wins9 = [  1, 72, 74,-20, 26, 49, 52,-25, 86,-72, 50, 97,
        -50,-36,-74, -4, 65,-70, 78, 85, 25,-14,-93,-16,
        -20,-24,  7, 28, -3, -5]

Travel routes between the casinos are represented by the following adjoinment matrix:

adj = [[1, 1, 0, 1, 0, 0, 0, 0, 0],
      [1, 1, 1, 0, 1, 0, 0, 0, 0],
      [0, 1, 1, 0, 0, 1, 0, 0, 0],
      [1, 0, 0, 1, 1, 0, 1, 0, 0],
      [0, 1, 0, 1, 1, 1, 0, 1, 0],
      [0, 0, 1, 0, 1, 1, 0, 0, 1],
      [0, 0, 0, 1, 0, 0, 1, 1, 0],
      [0, 0, 0, 0, 1, 0, 1, 1, 1],
      [0, 0, 0, 0, 0, 1, 0, 1, 1]]

You begin on the first day at the location of casino 1.

For example, if you were at casino #1 on day 1, you would win $53 if you decided to play. Later, if you were at casino #3 on day 4, you would lose $98 if you decided to play. Since you can only travel the distance of one route every night, you cannot reach all the casinos right away - e.g. you would not be able to play at casino #6 on the first day to win $68.

The casino owners don't like your special abilities, but they have agreed to let you play subject to the following conditions:

• At the beginning of the 30 days, you may either begin playing at your current casino immediately or decide to wait until the next day.
• Once you begin playing, you must play each consecutive day until you stop.
• Once you stop playing, you may not play again.

Each night after playing or not playing, you may either stay at your current location or travel to an immediately adjoining casino. You may travel overnight between casinos regardless of whether or not you have played that day.

You cannot play a fraction of a day; if a particular day is one where you have chosen to play, you will earn the predicted win or loss for that day.

You wish to determine how many N >= 0 days to not play, how many subsequent M >= 0 consecutive days to play (and how many remaining K >= 0 days you also don't play), and the path to travel between casinos during this 30-day time period such that you maximize your total winnings.