Today we start the review of a book called Triggers by Marshall Goldsmith. This is about how we react to stimuli that is against the nature of what we want to be to our spouse, friends and colleagues. We all get irritated or flustered at times. For example our temper may accelerate from zero to sixty when someone cuts us off on the road. Though the situation may seem out of control, how we respond is in our hands. This book teaches the following:
the most common belief triggers that keep us from changing
to identify our triggers and to use active questions to counter them
the power of the environment to influence behavior and the importance of the structure to change behavior
why a good enough attitude can harm interpersonal relationships

The book starts off with some facts of behavioral change:
1. Meaningful behavior change is very hard to do. Its hard to initiate behavioral change, even harder to stay the course, hardest of all to make the change stick.
There are usually three difficulties:
1. We can't admit that we need to change
2. we do not appreciate inertia's power over us. we prefer to do nothing.
3. we don't know how to execute the change.

2. No one can make us change unless we truly want to change. Change has to come from within.
If we want to be a better partner at home or a better manager at work, we not only have to change our ways but we have to get some buy-in from our partner or co-workers. Everyone around us has to recognize that we are changing.

There are belief triggers that stop behavioral change. We use these beliefs as articles of faith to justify our inaction and then wish away the result. These are called belief triggers and they are:
If i understand, I will do.
I have willpower and won't give in to temptation
Today is a special day and
At least I'm better than ...
I shouldn't need help and structure.
I won't get tired and my enthusiasm will not fade.
I have all the time in the world.
I won't get distracted and nothing unexpected will occur.
An epiphany will suddenly change my life
My change will be permanent and I will never have to worry again.
My elimination of old problems will not bring on new problems.
My efforts will be fairly rewarded.
No one is paying attention to me
If I change I'm not authentic ...
I have the wisdom to assess my own behavior...
#codingexercise
#interviewquestion
Given a continuous stream of alphabets determine if we have a palindrome or not. The stream is sending one character at a time.
The key to solving this is to keep track of the count of each character seen.
If the length of the string is even, then each character should appear a multiple of two times.
Else there can be at most one character with an odd count of 1

Bool isPalindrome ( stream s)
{
    var h = new Hashtable ();
    Char c = s.Read ();
    While ( c != EOF)
    {
       If (h.keys.contains (c)) {
            h [c] += 1;
       }
       Else {
             h.Add (c);
       }
       If (h.Values.Sum () %2 == 0)
        {
            Foreach  (int val in Values) {
               If (val % 2 != 0) {
                     Return false;
               }
            }
}
else
{
Int count = 0;
Foreach  (int val in Values) {

               If (val % 2 != 0) {

                     count += 1;

               }
               if (count > 1)
                     return false;
}
    }
return true;
}

#codingexercise
#interviewquestion
Given a board like Othello, flip the coins in horizontal and vertical directions on a move.
void flip (ref int[,] board, int x, int y, int color)
{
    int i = x-1;
    while (i > 0){
       if (board[i,y] == color)
          for (int k = i+1; k < x; k++)
             board[k,y] = color;
        i--;
     }

     i = x+1;
     while (i < N){
       if (board[i,y] == color)
          for (int k = x+1; k < i; k++)
             board[k,y] = color;
        i++;
     }

    int j = y-1;
    while (j > 0){
       if (board[x,j] == color)
          for (int k = j+1; k < y; k++)
             board[x,k] = color;
        j--;
     }

     j = y+1;
     while (j < N){
       if (board[x,j] == color)
          for (int k = y+1; k < j; k++)
             board[x.k] = color;
        j++;
     }

}

Today we continue writing the review of the book "Little bets".  In investigating what facilitates the successful practice of little bets, a certain way of thinking about failure plays an important role. Successful experimental innovators tend to view failure as both inevitable and instrumental in pursuing their goals. Therefore they exhibit a growth mindset and tend to seek activities that expand their abilities. For example, Pixar's top managers demonstrate a relentless desire to challenge and learn, and they ensure that this trickles throughout the rest of the company.Ed Catmull of Pixar describes the creative process there as going from suck to nonsuck. The author also interviewed Frank Gehry who is a well known architect and demonstrates growth mindset. He said he doesn't feel he is at a mountaintop but is still continuing to get there. Practicing little bets frees us from the expectation that we should know everything we need to know before we begin. By focusing on doing rather than planning and learning the pitfalls of ideas, we demonstrate a growth mindset. Pixar relies on a concept called plussing. The idea of plussing is to build upon and improve ideas without using judgemental language. Creating an atmosphere where ideas are constantly being plussed, maintains a sense of humour and playfulness. Successful humour breaks down power structures that tend to inhibhit tighter social bonds and interactions.
The author extolls constraints in any situation as guardrails that not only shape and focus problems but also provide clear challenges. Bing Gordon, the founder of Electronic Arts found it useful to break down a project into relatively small problems - a method he called smallifying. This practice has now been widely embraced in the software industry as agile software development. Similarly Yunus the well known Economics professor absorbed himself in the lives of the poorest before discovering a core problem that economists had ignored.
Learning a little from a lot and a lot from a little are some of the insights that comes with this creativity. Dr.Wiseman found that people who considered themselves lucky  in essence created their own luck by interacting with a larger group and getting more insights and opportunities. Similarly MIT Professor Von Hippel found that there are cutting edge users of ideas who form a good pilot group to test little bets which make them a sure win over a bigger audience. When the audience gives a muted chorus of chuckles, Chris Rock knows that he's found a theme that has the makings of  a good joke.
Starbucks evolved in a similar manner. It emerged by carefully adapting to customer feedback. Schultz initially was against non-fat milk but when customers kept requesting non-fat milk, he relented. The success of those drinks become an important small win. Non-fat milk would grow to almost half of Starbucks' lattes and cappuccinos.
Thus experimental innovators use strikingly similar methods inside their work processes.

Today we write a summary of the book "Little Bets" by Peter Sims.  This book is about an approach that many successful professionals take : methodically taking small experimental steps.From Beethoven to Edison to Bezos, these achievers practice a set of simple but often counterintuitive experimental methods - often failing quickly to learn, trying imperfect ideas and engaging in highly immersed observation. These methods unshackle them from conventional planning, unexpected connections and perceiving invaluable insights.
This book tells us
how to embrace failure as a critical step towards success
harness your curiosity with examples from successful companies
steps to use little bets for possibly bigger outcomes
leverage small wins to improve performance goals
The book mentions examples of how comedian Chris Rock experiments many ideas before a small audience before making the final cut. Bezos champions developing ideas in new markets to "planting seeds" and "going down blind alleys". At the core of this approach, little bets are concrete actions taken to discover, test and develop ideas that are achievable and affordable.They begin as creative possibilities that get iterated and refined over time. This is an approach that anyone can take.
The steps are
experiment - learn by doing and failing quickly to learn fast
play - a playful and humorous atmosphere relaxes inhibitions
immerse - gather fresh ideas and insights
define - use insights gathered to define specific problems
reorient - be flexible in pursuit of larger goals
iterate - repeat, refine and test frequently
As an example. HP introduced the scientific calculator as a little bet. Today they are ubiquitous.
Prof.Saras Sarasvathy says there are two advantages - it enables us to focus on what we can afford to lose rather than make assumption of what we can gain and secondly it develops the means as we progress. Determining what he can afford to lose is what Chris Rock does when going before audiences with rough material. Throughout Pixar's creative process, they rely heavily on what they called plussing - to build upon and improve ideas without using judgemental language. What Chris Rock and Pixar animations show is that they use little bets to discover, test and develop ideas that are achievable. These examples goto show that little bets can improve the overall progress.

#codingexercise
Int [] Merge ( int [] sorted1, int [] sorted2)
{
Int I =0, j = 0;k=0;
Int m = sorted1.length;
Int n = sorted2.length ;
Var  results = new int [sorted1. Length +sorted1.length.length];
While ( i < m && j < n)
{
If sorted1  [i] < sorted [2] {
i++;
Results [k] = sorted1 [i]}
Else{
Rsults  [k] = sorted2[j];
J++;
}
K++;
}
While (I < m){
   Results [k] = sorted [i];
    I++;
     K++;}

While j < n{
     Results  [k] = sorted2 [j];
      J++;
      K++;}
Return results;
}

Int[] Merge (int [] sorted1, int [] sorted2)
{
Var results = new List <int>();
Int m=0,n =0;
For ( int I = 0; I < sorted1.length + sorted2.length; i++){
If (sorted1 [m]  < sorted2[n])
results [k] == sorted1 [m];
m++;
}
Else  {
Results [k] == sorted2 [n];
n++;
}
Return results.toArray ();
}

Today we discuss a book review of "Data-ism" by Steve Lohr - a Harper Collins publication. Technology has an unimaginable capacity to generate data. This raises concerns about the idolatry of data and the consequent replacement of wisdom with quantification - a phenomenon named post-humanist. The author includes description of the possibilities of big data.
He starts off with an example of McKesson corporation which distributes one third of all pharmaceuticals in the US to 26000 customer locations including roughly 240 million pills a day.
The author takes this example because the company accumulates data (pills, prices and shipment miles) which is plentiful, stable and reliable. This has enabled IBM to build a sort of flight simulator for decision making. Presumably the author is talking about online data and data warehousing and goes to add that this capability works in two ways - one to provide profit and loss figures for every product, supplier and another to provide a tool for analytics and prediction.
An outcome of such analytics has been to centralize the distribution of very expensive drugs. Centralization requires expensive air shipments to customers. However, IBM's modeling software predicted that savings in inventory levels for certain drugs would make up the higher air freight expenses. McKesson tested this with a pilot project and the proposal was vindicated. The software gave McKesson the clarity and confidence to go ahead. This is an example where quantification trumps "best guesses, gut feel, experience and intuition". This replacement of "wisdom" can cause concerns.
The author can be credited with not only highlighting the benefits but as a journalist striving to see all sides of the issues. As an example, he cites Tom Mitchell, the chairman of machine-learning department at Carnegie Mellon who gave an example involving two sentences:
The girl caught the butterfly with the spots.
The girl caught the butterfly with the net.
where humans can understand that girls don't have spots and butterflies don't have nets but machines are missing what can be termed as "context"
The role of context can be understood with say the number 39 which means nothing but add Celsius and it means temperature and hot and add a person's name and it means illness.
Context today is said to be achieved in two ways - correlation and association.  Fortunately correlation is not new and data mining has helped here. For example, Walmart found out about ten years earlier that consumers stocked up on strawberry pop tarts and beer before a hurricane.
Another example given is that of Zest Finance that reduces the risk of payday borrowers by including data points such as whether the borrower has a cell phone and if he or she types their names in all upper case. Although it works, not knowing "why" there is a correlation brings up a debate. Lohr says that the authors of Big Data insist that big data overturns the self congratulatory illusion that comes with identifying causal mechanisms.
Data enthusiasts say the why can be answered by pairing models with measurements. However measurements seems to have led us to say the housing financial crisis where data was analyzed that was plentiful and ignored financial crises, when data sets were sparse and messy.
Therefore correlation alone is not sufficient. But intuition has its own problems. The author cites the example from Daniel Kahneman's  - "Thinking, Fast and slow" where participants asked if a man described as "meek" will be a librarian or a farmer. While the vast majority replied "librarian", data showed that there are twenty times more farmers than librarians.
Since both man and machine have weaknesses, the authors say that both can help each other remove their blindspots. However, he warns against froming a habit where instead of computers assisting humans, humans may assist computers
Another example of a frontline of this interdependence is a medical center where doctors and data driven software are playing "an information game". Doctors no longer reign supreme over monitoring. Lohr points out that the two can augment each other.

Today we discuss a book review summary of the book  "How the World sees you" by Sally Hogshead with the motto - Discover your highest value through the science of fascination
There is power in understanding how the world sees you : you appear confident, authentic and ready to make a positive impression. This book gives a step by step method to describe yourself in one or two words which then becomes your tag. This book helps you with some of the terms. Your slogan helps you  in all walks of life from writing that self-introduction on a new job to pitching your profile on LinkedIn.
This book differs from some self-improvement books in that it does not ask you to change but to be more of who you are. It should help you better relationships and grow your business.
This book focuses on the seven fascination advantages and its discussion.
When we are born, we are automatically fascinating to the world with our gestures but over time we acquire layers of what makes us boring. For example, you don't want to stand out with your ideas or present them as insipid as possible to avoid attracting criticism. We want to become unnoticed when we want to avoid being seen as unworthy. However hiding works temporarily and usually backfires. Sometimes we feel we don't have anything noteworthy but that only dulls our edges.
As conversations become compressed in a more crowded marketplace, you need to know your strength and your differences. We need to know our values and the highest distinct value.
Likability and leadership are improved with fascination advantages. With such an advantage, when you talk, people will listen and remember you and even anticipate your messages.
One example of why this is important is given by the experiment of Joshua Bell. As a famous violinist, he could command a lot of money for his skills. When he agreed to participate in an arranged experiment to play in a subway station, the throng passed by in their rush. This tells us that no matter how good we are, we need to do more to fascinate others in a highly demanding environment.
There are three deadly threats in a competitive environment:
Distraction - that threatens the connection with others. Typically a listener only gives the first nine seconds You have to add value in that golden window
Competition  - which threatens your ability to differentiate and win. Customers want to try out something different. And you are already different.
Commoditization - which threatens your relationships and loyalty. This can seep into your relationships and erode your connections to the point of being replaced.
You can triumph by adding distinct value: This makes yobyu become admired for a noteworthy ability and for being worth more than you are being paid. You deliver more than you would normally be expected. You become preferred even if you are more expensive or less convenient.
Highest Distinct Value has a meaning in each word.You discover it by recollecting what it means to be in fascination. Its the state of being completely engaged mentally, emotionally and physically.
The Art of Fascination comes with the triumph of adding distinct value over the threats of distraction, competition and commoditization.  The key here is to fully recognize your differences rather than just the strengths. When you communicate, you are either adding value or taking up space. That's why those "Touchpoints" are important. Every touch point should highlight why you are different and better. Maximize value and subtract everything else.
The  Seven Fascination Advantages are
1) the power advantage - leading through authority where the power personalities speak the language of confidence. You will take charge of the conversation because you are decisive and self-assured.
2) the passion advantage - you create warm emotional connections. You are approachable and gregarious. Use reassuring terms such as "you bet"
3) the mystique advantage - This is about thinking before speaking. Mystique personalities speak the language of listening. You see nuances and you think things through.
4) the prestige advantage - Achieving success with higher standards You should speak the language of excellence
5) the alert advantage - You use careful precision. You speak details where it matters. They are risk averse.
6) the innovation advantage - You speak the language of creativity. You propose unexpected solutions or come up with a profusion of ideas.
7) the trust advantage - you pay attention to building loyalty over time.
At this point you should list your advantages as primary + secondary to articulate your highest distinct value.

#codingexercise
Given a binary tree implement an iterator that will iterate through its elements.
public interface ITreeEnumerator
{
 bool MoveNext();
 void Reset();
}

public class TreeEnum: ITreeEnumerator
{
   Stack<Node> inorder = new Stack<Node>();
   Node current = null;
   Node root = null;
   public TreeEnum(TreeNode n){
       root = n;
       Leftmost(n);
   }
   private void Traverse() {
      current = inorder.pop();
      Leftmost(current.right);
   }
   public void Leftmost(Node n){
     while (n != null) {
              inorder.Push(n);
              n = n.left;
     }
   }
  public bool MoveNext() {
      if (inorder.IsEmpty() == False) {
          traverse();
          return true;
      }
      return false;
  }
 public void Reset() {
   if (root){
           Leftmost(root);
   }      
 }
}

Implementation of partition method in quicksilver
int partition ( ref int [] A, int start, int end){
Int I = start - 1;
Int r = end - 1;
For ( int j = start; j < r; j++)
{
    If ( A [ j ] < =A [r] ) {
         i = i + 1;
         Swap ( A[i] , A [j] );
    }
 }
   Swap (A [i+1], A [r]);
return i + 1;
}

Today we discuss a coding problem.
Question: Given a series of numbers from 1 to pow (2, n) on a paper, we fold it in the following way  with the help of two commands
L : Fold the paper from left edge to right edge
R : Fold the paper from right edge to left edge
For n = 1 we have numbers 1,2
These can be folded in two ways L & R
L makes the number 1 come on top of 2
R makes the number 2 come on top of 1
And a sequence of alternating L and R.
After n number of commands there will be a number in each layer
We have to print it from top to bottom as
{1,2} in this case.
Solution Note that folding only involves left and right commands
And this is repeated for log N steps
If we maintain a list for each index, folding causes elements to be added onto each index from another index.
In each step these lists on either side of the center come closer until there is only one.
With a data structure as a list of list for current and previous iterations,
We can iterate for log N steps and merge according to whether the command is left or right

// partial code
List<int> Fold(List<int> numbers>)
{
string command = "L";
var curr = new List<List<int>> ();

for (int i = 0; i < numbers.Length; i++)
{
      curr.append (new List<int>(){ numbers[i]});
}

For (int i = 0; i < curr.length/2; i++)
{
       if (command == "L")
       {
            for (k = 0; k < curr.length / 2; k++)
                Merge(ref curr, k, length-1-k);
            LeftShift(curr, curr.length/2);
       }
       else
       {
            for (k=0; k < curr.lenght / 2; k++)
                Merge(ref curr, length-1-k, k)
            RightShift(curr, curr.length/2);
       }
}
return curr[0];
}

void Merge(ref List<List<int>> curr, int src, int dest)
{
// source will have its list reversed and pushed at the front of the list on destination
// source list will be set to null
}
LeftShift and RightShift will trim the left and right null lists.

Another question along similar lines is that there are two arrays given and we can sort all the elements of array A in the order of B. Then the remaining elements of A can be sorted in that order.

Question : Given an array where each element is maximum +-k index away from its sorted position, find an algorithm to sort such array. 

Solution : We will assume n = number of elements in array is greater than k.  

 

One solution is to use InsertionSort. It will benefit from the property of the given array because it won't have to traverse the entire length of the array in the worst case. 

The Insertion sort goes like this :  

for int i = 1 to len(A) -1 

   j = i 

   while( j > 0 and A[j-1] > A[j]) 

       swap(A[j] and A[j-1]) 

       j = j - 1 

 

 

Another algorithm cited online was to use a heap of size 2K. As the elements fill up, we could take the minimum and output it. This does not affect the input array.  

However this will not work because the heapsize has to be all the elements of the array for this kind of sorting to work because the choice of the first 2k elements does not guarantee that the successor of the next element will be found  

 

 

Question: Given a string left rotate it by a given number of times. 

Answer: Let us first write it down as it is described. 

void Rotate(Stringbuilder b, int n) 

while (n) 

  char c = b.removeAt(0) 

  b.append(c) 

  n-- 

return b; 

Next the optimal solution would be to split the string at the index and swap the two partitions 

 

Question: Given a number between 0 to 1000, raise 11 to that number and determine the count of times '1' appears in the result. 

Answer: Generate the Pascal numbers with levels upto and inclusive of that number. Then for each number appearing at that level test and count the number of ones. 

 

Question: given a string of characters x and o where x and o are interspersed, find the cheapest way to group all the x together. Each movement of a letter is expensive. 

Answer: we can find the weighted average of the index by taking a weight of 1 for all x and a weight of 0 for all o. Then we can shift all the x’s closer together to this index. 

Question Write SQL to calculate the number of work days  between two dates
Answer:
SELECT (DATEDIFF(dd, @StartDate, @EndDate)+1) - (DATEDIFF(wk,@StartDate,@EndDate)*2)
-(CASE WHEN DATENAME(dw, @StartDate) = 'Sunday' THEN 1 ELSE 0 END)
-(CASE WHEN DATENAME(dw, @EndDate)='Saturday' THEN 1 ELSE 0 END)

 
Question: Design a file search utility
Answer: A depth first traversal with escape for current and parent folder notations.