Merge pull request #179 from rasik210/twostrings

 Two strings problem:C# solution

Algorithms/Strings/Two Strings/Solution.cs

@@ -0,0 +1,56 @@
+/*
+         Problem: https://www.hackerrank.com/challenges/two-strings/problem
+         C# Language Version: 6.0
+         .Net Framework Version: 4.7
+         Tool Version : Visual Studio Community 2017
+         Thoughts (Key points in algorithm):
+         - It is about finding just one character in first string which will also be present in second string.
+         - Iterate the first string and create a set (hash set for O(1) ammortized searching) of all the english alphabet characters appearing in it.
+         - Then, iterate the second string and check if any of the characters appearing is present in the character set of first string.
+         - If found print YES else print NO.
+
+         Gotchas:
+          <None>
+
+         Time Complexity:  O(m + n) //m and n are length of the input strings respectively.
+         Space Complexity: O(1) 
+
+        */
+using System.Collections.Generic;
+using System;
+
+class Solution {
+    static void Main(string[] args) {
+       var testcaseCount = int.Parse(Console.ReadLine());
+            while (testcaseCount > 0)
+            {
+                var text1nextChar = Console.Read();
+                var charMap = new HashSet<int>();
+                //special handling for hacker rank execution environment.
+                //for line break they use '\n' whose ascii code is 10
+                //on my local box I use 13 which is ascii code for '\r'
+                while (text1nextChar != 10)
+                {
+
+                        if (!charMap.Contains(text1nextChar))
+                            charMap.Add(text1nextChar);
+
+                    text1nextChar = Console.Read();
+                }
+
+                var charFound = "NO";
+                var text2nextChar = Console.Read();
+                //special handling for hacker rank execution environment.
+                //for end of file they use -1 which is the end of second string of last test case.
+                while (text2nextChar != 10 && text2nextChar != -1)
+                {
+                    if (charMap.Contains(text2nextChar) && charFound != "YES")
+                        charFound = "YES";
+                    text2nextChar = Console.Read();
+                }
+
+                Console.WriteLine(charFound);
+                testcaseCount--;
+            }
+    }
+}

README.md

@@ -178,7 +178,7 @@
 |   | [Anagram](https://www.hackerrank.com/challenges/anagram)| <ul><li>[Java](./Algorithms/Strings/Anagram/Solution.java)</li><ul> | _O(n)_ | _O(1)_ | Easy | 25| ||
 |   | [Making Anagrams](https://www.hackerrank.com/challenges/making-anagrams)| <ul><li>[Java](./Algorithms/Strings/Making%20Anagrams/Solution.java)</li><ul> | _O(n)_ | _O(n)_ | Easy | 30| ||
 |   | [Game of Thrones - I](https://www.hackerrank.com/challenges/game-of-thrones)| <ul><li>[Java](./Algorithms/Strings/Game%20of%20Thrones-I/Solution.java)</li><li>[C#](./Algorithms/Strings/Game%20of%20Thrones-I/Solution.cs)</li><ul> | _O(n)_ | _O(1)_ | Easy | 30| ||
-|   | [Two Strings](https://www.hackerrank.com/challenges/two-strings)| <ul><li>[Java](./Algorithms/Strings/Two%20Strings/Solution.java)</li><ul> | _O(&#124;a&#124; + &#124;b&#124;)_ | _O(1)_ | Easy | 25| ||
+|   | [Two Strings](https://www.hackerrank.com/challenges/two-strings)| <ul><li>[Java](./Algorithms/Strings/Two%20Strings/Solution.java)</li><li>[C#](./Algorithms/Strings/Two%20Strings/Solution.cs)</li><ul> | _O(&#124;a&#124; + &#124;b&#124;)_ | _O(1)_ | Easy | 25| a and b are lengths of the input strings ||
 |   | [String Construction](https://www.hackerrank.com/challenges/string-construction)| <ul><li>[Java](./Algorithms/Strings/String%20Construction/Solution.java)</li><ul> | _O(n)_ | _O(n)_ | Easy | 25| ||
 |   | [Sherlock and Valid String](https://www.hackerrank.com/challenges/sherlock-and-valid-string)| <ul><li>[Java](./Algorithms/Strings/Sherlock%20and%20Valid%20String/Solution.java)</li><ul> | _O(n)_ | _O(n)_ | Hard | 100| ||
 |   | [Richie Rich](https://www.hackerrank.com/challenges/richie-rich)| <ul><li>Java</li> <li>[Python3](./Algorithms/Strings/Richie%20Rich/solution.py)</li><ul> | _O(n)_  | _O(n)_ | Medium | 30| ||