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Hackerrank - Quicksort 2 - Sorting

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     Problem Submissions Leaderboard Discussions In the previous challenge, you wrote a partition method to split an array into two sub-arrays, one containing smaller elements and one containing larger elements than a given number. This means you 'sorted' half the array with respect to the other half. Can you repeatedly use partition to sort an entire array? Guideline In Insertion Sort, you simply went through each element in order and inserted it into a sorted sub-array. In this challenge, you cannot focus on one element at a time, but instead must deal with whole sub-arrays, with a strategy known as "divide and conquer". When partition is called on an array, two parts of the array get 'sorted' with respect to each other. If partition is then called on each sub-array, the array will now be split into four parts. This process can be repeated until the sub-arrays are small. Notice that when partition is called on just one of the numbers, the...
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Hackerrank - CaesarCipher

  Julius Caesar protected his confidential information by encrypting it using a cipher.   Caesar's cipher   shifts each letter by a number of letters. If the shift takes you past the end of the alphabet, just rotate back to the front of the alphabet. In the case of a rotation by 3, w, x, y and z would map to z, a, b and c. Original alphabet: abcdefghijklmnopqrstuvwxyz Alphabet rotated +3: defghijklmnopqrstuvwxyzabc Example The alphabet is rotated by  , matching the mapping above. The encrypted string is  . Note:  The cipher  only  encrypts letters; symbols, such as  - , remain unencrypted. Function Description Complete the  caesarCipher  function in the editor below. caesarCipher has the following parameter(s): string s : cleartext int k : the alphabet rotation factor Returns string:  the encrypted string Input Format The first line contains the integer,  , the length of the unencrypted string. The second line cont...
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Hackerrank - Prepare | Data Structures | Linked Lists | Get Node Value

  This challenge is part of a tutorial track by   MyCodeSchool Given a pointer to the head of a linked list and a specific position, determine the data value at that position. Count backwards from the tail node. The tail is at postion 0, its parent is at 1 and so on. Example  refers to  Each of the data values matches its distance from the tail. The value   is at the desired position. Function Description Complete the  getNode  function in the editor below. getNode  has the following parameters: SinglyLinkedListNode pointer head:  refers to the head of the list int positionFromTail:  the item to retrieve Returns int:  the value at the desired position Input Format The first line contains an integer  , the number of test cases. Each test case has the following format: The first line contains an integer  , the number of elements in the linked list. The next   lines contains an integer, the data value for an el...
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