Yammer the private social network, release their SDK for Windows Phone 8 and iOS. The SDKs enable you to add Yammer OAuth 2-based authentication to your smartphone and tablet apps. Once authenticated, you can use the SDKs to make REST calls to read/write from the Yammer API, thus integrating the full spectrum of Yammer’s social services into your mobile app.

To start building your Yammer Mobile App, visit the Yammer Developer Site for more information:https://developer.yammer.com/mobile.

Today I have to get a list of all tables present in database. I used following query to get the list of all tables present in SQL Server Database.

SELECT TABLE_NAME  
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE' order by TABLE_NAME 

Today we have to write a program for reversing a Doubly linked list. A doubly-linked list is a linked data structure that consists of a set of sequentially linked records called nodes. Each node contains two fields, called links, that are references to the previous and to the next node in the sequence of nodes. The beginning and ending nodes’ previous and next links, respectively, point to some kind of terminator, typically a sentinel node or null, to facilitate traversal of the list. If there is only one sentinel node, then the list is circularly linked via the sentinel node. It can be conceptualized as two singly linked lists formed from the same data items, but in opposite sequential orders.

Source : http://en.wikipedia.org/wiki/Doubly-linked_list

Code

        public DoubleNode<T> Reverse()
        {
            DoubleNode<T> newHead = null;
            while (head != null)
            {
                DoubleNode<T> temp = head;
                head = head.Next;
                temp.Next = newHead;
                newHead = temp;
            }
            return newHead;
        }

Input : 0->1->2->3->4->5->6->7->8->9->

output: 1->0->3->2->5->4->7->6->9->8->

Code :

        public void SwapEverySecondElement()
        {
            var p = head;
            var q = p.Next;

            while (q != null)
            {
                var temp = p.Data;
                p.Data = q.Data;
                q.Data = temp;
                p = q.Next;
                if (p != null)
                {
                    q = p.Next;

                }
                else
                {
                    q = null;
                }

            }

        }

Test

Input

0->1->2->3->4->5->6->7->8->9->

Output

1->0->3->2->5->4->7->6->9->8->

——————————————————————————–

Input

A->B->C->D->E->F->G->H->I->J->K->L->M->N->O->P->Q->R->S->T->U->V->W->X->Y->Z->

Output

B->A->D->C->F->E->H->G->J->I->L->K->N->M->P->O->R->Q->T->S->V->U->X->W->Z->Y->

Today we will write a program for printing a given string’s in triangle.

For Example

input : Independence

Output

Code

For First Image

        public static void PrintStringInTriangle(this string input)
        {
            int length = input.Length;

            for (int i = 0; i < length; i++)
            {
                for (int spaceCounter =0; spaceCounter <=length-i; spaceCounter++)
                {
                    Console.Write(" ");
                }
                for (int charCounter = 0; charCounter <=i; charCounter++)
                {
                    Console.Write(input[charCounter]);
                    Console.Write(" ");
                }
                Console.WriteLine("");
            }


        }

For Second Image

        public static void PrintStringInLeftTriangle(this string input)
        {
            int length = input.Length;

            for (int i = 0; i < length; i++)
            {
                for (int spaceCounter = 0; spaceCounter <= length - i; spaceCounter++)
                {
                    Console.Write(" ");
                }
                for (int charCounter = 0; charCounter <= i; charCounter++)
                {
                    Console.Write(input[charCounter]);
                     
                }
                Console.WriteLine("");
            }


        }

For Third Image

        public static void PrintStringInRightTriangle(this string input)
        {
            int length = input.Length;

            for (int i = 0; i < length; i++)
            {
                for (int spaceCounter = 0; spaceCounter <= length; spaceCounter++)
                {
                    Console.Write(" ");
                }
                for (int charCounter = 0; charCounter <= i; charCounter++)
                {
                    Console.Write(input[charCounter]);

                }
                Console.WriteLine("");
            }


        }

Today we will write a program for creating a two dimensional Array from a input file.

Steps.

1. Read input File.
2. Calculate the row and column count.
3. Read File line by line, split line by given delimiter and create two dimensional array.

C# Code

        public static int[,] Create2DMatrixFromFile(string inputFile
                                                   , char columnDelimiter)
        {

            if (File.Exists(@inputFile) == false)
            {
                throw new FileNotFoundException("Input file is not present ");
            }
            // Read All line from file

            string[] allLine = File.ReadAllLines(@inputFile);
            int rowCount = allLine.Count();

            int columnCount = allLine[0].Split(new char[] { columnDelimiter }, 
                                      StringSplitOptions.RemoveEmptyEntries).Count();

            int[,] matrix = new int[rowCount, columnCount];

            for (int rowCounter = 0; rowCounter < rowCount; rowCounter++)
            {
                string[] line = allLine[rowCounter].Split(columnDelimiter);
                for (int columnConter = 0; columnConter < columnCount; columnConter++)
                {
                    matrix[rowCounter, columnConter] = int.Parse(line[columnConter]);
                }

            }
           return matrix;

        }

input File 

11,12,13,14,15
21,22,23,24,25
31,32,33,34,35
41,42,43,44,45
51,52,53,54,55
16,17,18,19,20
26,27,28,29,30
36,37,38,39,40
46,47,48,49,50

Today we will write a program to print a given matrix in diagonal order.

        public void DiagonalOrder(int[,] input)
        {
            int rowcount = input.GetLength(0);
            int columnCount = input.GetLength(1);
            int rowIndex = -1;
            int columnIndex = 0;
            int startRowIndex = rowIndex;
            int startColumnIndex = columnIndex;
            while (true)
            {
                if (rowIndex < rowcount - 1)
                {
                    rowIndex++;
                }
                else if (rowIndex == rowcount - 1 && columnIndex < columnCount - 1)
                {
                    columnIndex++;
                }
                else if (rowIndex == rowcount - 1 && columnIndex == columnCount - 1)
                {
                    break;
                }
                startRowIndex = rowIndex;
                startColumnIndex = columnIndex;
                while (startRowIndex < rowcount && startRowIndex >= 0
                        && startColumnIndex < columnCount && startColumnIndex >= 0)
                {
                    Console.Write(input[startRowIndex, startColumnIndex] + " , ");
                    startRowIndex = startRowIndex - 1;
                    startColumnIndex = startColumnIndex + 1;

                }
                Console.WriteLine("");
            }
        }

input

1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50

output

1 ,
11 , 2 ,
21 , 12 , 3 ,
31 , 22 , 13 , 4 ,
41 , 32 , 23 , 14 , 5 ,
42 , 33 , 24 , 15 , 6 ,
43 , 34 , 25 , 16 , 7 ,
44 , 35 , 26 , 17 , 8 ,
45 , 36 , 27 , 18 , 9 ,
46 , 37 , 28 , 19 , 10 ,
47 , 38 , 29 , 20 ,
48 , 39 , 30 ,
49 , 40 ,
50 ,

————————————————————————————————————————

input

11 12 13 14 15
21 22 23 24 25
31 32 33 34 35
41 42 43 44 45
51 52 53 54 55
16 17 18 19 20
26 27 28 29 30
36 37 38 39 40
46 47 48 49 50

Output

11 ,
21 , 12 ,
31 , 22 , 13 ,
41 , 32 , 23 , 14 ,
51 , 42 , 33 , 24 , 15 ,
16 , 52 , 43 , 34 , 25 ,
26 , 17 , 53 , 44 , 35 ,
36 , 27 , 18 , 54 , 45 ,
46 , 37 , 28 , 19 , 55 ,
47 , 38 , 29 , 20 ,
48 , 39 , 30 ,
49 , 40 ,
50 ,

        public static char MaximumOccurringCharacter(this string input)
        {
            SortedDictionary<char, int> charDict = new SortedDictionary<char, int>();
            int length = input.Length;

            for (int i = 0; i < length; i++)
            {
                if (charDict.ContainsKey(input[i]))
                {
                    charDict[input[i]]++;
                }
                else
                {
                    charDict.Add(input[i], 1);
                }
            }

            var max = charDict.Values.Max();
            var relevantKeys = charDict.Where(pair => max.Equals(pair.Value))
                .Select(pair => pair.Key).First();
            return relevantKeys;

        }

Test Case

Console.WriteLine("Max occur char in string test is : " + "test".MaximumOccurringCharacter());

Console.WriteLine("Max occur char in string maximum is : " + "maximum".MaximumOccurringCharacter());

Console.WriteLine("Max occur char in string MaximumOccurringCharacter is : " + "MaximumOccurringCharacter".MaximumOccurringCharacter());

Output

Max occur char in string test is : t
Max occur char in string maximum is : m
Max occur char in string MaximumOccurringCharacter is : r

For finding the height of the tree we can use level order traversal of three. We  need to traverse the tree level by level and increment the height count.

        public int IterativeHeightOfTree(TreeNode root)

        {

            int height = 0;

            if (root == null)

            {

                return height;

            }

            int nodes = 0;

            Queue<TreeNode> queue = new Queue<TreeNode>();

            queue.Enqueue(root);

            while (true)

            {

                nodes = queue.Count();

                if (nodes == 0)

                {

                    return height;

                }

                height = height + 1;

                while (nodes > 0)

                {

                    var temp = queue.Dequeue();

                    if (temp.Left != null)

                    {

                        queue.Enqueue(temp.Left);

                    }

                    if (temp.Right != null)

                    {

                        queue.Enqueue(temp.Right);

                    }

                    nodes = nodes - 1;

                }

            }

            //return height;

        }

Test Case

Tree Node count is :  20
5,3,9,15,13,9,7,18,2,13,1,5,7,19,13,13,6,12,14,14,
Height of Tree is 5

Tree Node count is :  1
1,
Height of Tree is 1

Tree Node count is :  0
Height of Tree is 0

Below solution divides the problem into sub problems of size y/2 and call the sub problems recursively

public static UInt64 Power(UInt64 x, UInt64 n)
{
    if (n == 0)
        return 1;
    else if (n % 2 == 0)
        return Power(x, n / 2) * Power(x, n / 2);
    else
        return x * Power(x, n / 2) * Power(x, n / 2);

}

Test Case

UInt64 x = 0;
UInt64 n = 0;
x = 2; n = 2;
Console.WriteLine(string.Format("{0}^{1} ={2}", x, n, Power(x, n)));
x = 2; n = 3;
Console.WriteLine(string.Format("{0}^{1} ={2}", x, n, Power(x, n)));
x = 10; n = 2;
Console.WriteLine(string.Format("{0}^{1} ={2}", x, n, Power(x, n)));
x = 12; n = 18;
Console.WriteLine(string.Format("{0}^{1} ={2}", x, n, Power(x, n)));
Console.Read();

Output

2^2 =4
2^3 =8
10^2 =100
12^18 =8176589207175692288