HackerRank: Circular Array Rotation

Problem

John Watson performs an operation called a right circular rotation on an array of integers, [a(0),a(1).a(2)...a(n-2),a(n-1)]. After performing one right circular rotation operation, the array is transformed from

[a(0),a(1).a(2)...a(n-2),a(n-1)]

to

[a(n-1),a(0),a(1).a(2)...a(n-2)].

Watson performs this operation k times. To test Sherlock’s ability to identify the current element at a particular position in the rotated array, Watson asks q queries, where each query consists of a single integer, m, for which you must print the element at index in the rotated array (i.e., the value of a(m)).

Input Format

The first line contains space-separated integers, n, k, and q, respectively.
The second line contains space-separated integers, where each integer i describes array element a(i)(where 0 <= i <= n).
Each of the q subsequent lines contains a single integer denoting m.

Constraints

  • 0 <= i <= 10^5
  • 0 <= a(i) <= 10^5
  • 0 <= k <= 10^5
  • 0 <= q <= 500
  • 0 <= m <= N-1

Output Format

For each query, print the value of the element at index m of the rotated array on a new line.

Sample Input
3 2 3
1 2 3
0
1
2
Sample Output
2
3
1

Explanation

After the first rotation, the array becomes [3,1,2].
After the second (and final) rotation, the array becomes [2,3,1].

Let’s refer to the array’s final state as array b. For each query, we just have to print the value of b(m) on a new line:

  • m=0 , so we print 2 on a new line.
  • m=1 , so we print 3 on a new line.
  • m=2 , so we print 1 on a new line.

Soluton


HackerEarth: Battle Of Bots 6: Draughts

Problem:

Sample Game

Draughts is a two player board game which is played on a 8X8 grid of cells and is played on opposite sides of the game-board. Each player has an allocated color, Red ( First Player ) or White ( Second Player ) being conventional. Players take turns involving diagonal moves of uniform game pieces in the forward direction only and mandatory captures by jumping over opponent pieces.

Rules:

  • Player can only move diagonally to the adjacent cell and in forward direction, if the diagonally adjacent cell is vacant.
  • A player may not move an opponent’s piece.
  • If the diagonally adjacent cell contains an opponent’s piece, and the cell immediately beyond it is vacant, the opponent’s piece may be captured (and removed from the game) by jumping over it in the forward direction only.
  • If a player made a jump, then its mandatory to keep on jumping as long as the jump is possible.
  • Player cannot move to the diagonally adjacent cell once the player made a jump.

The game will end when any of the players don’t have any move left. At the end of the game the player with majority of pieces will win.

We will play it on an 8X8 grid. The top left of the grid is [0,0] and the bottom right is [7,7].

Input:
The input will be a 8X8 matrix consisting only of 0o2. Then another line will follow which will contain a number –  1 or 2 which is your player id. In the given matrix, top-left is [0,0] and bottom-right is [7,7]. The x-coordinate increases from left to right, and y-coordinate increases from top to bottom.

The cell marked 0 means it doesn’t contain any stones. The cell marked 1 means it contains first player’s stone which is Red in color. The cell marked 2 means it contains second player’s stone which is white in color.

Output:
In the first line print the coordinates of the cell separated by space, the piece he / she wants to move.
In second line print an integer N, number of steps or jumps the piece will make in one move.
In the next N lines print the coordinates of the cells in which the piece will make jump.
You must take care that you don’t print invalid coordinates. For example, [1,1] might be a valid coordinate in the game play if [1,1] in diagonal to the piece in which is going to jump, but [9,10] will never be. Also if you play an invalid move or your code exceeds the time/memory limit while determining the move, you lose the game.

Starting state
The starting state of the game is the state of the board before the game starts.

0 1 0 1 0 1 0 1
1 0 1 0 1 0 1 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 2 0 2 0 2 0 2
2 0 2 0 2 0 2 0

First Input
This is the input give to the first player at the start of the game.

0 1 0 1 0 1 0 1
1 0 1 0 1 0 1 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 2 0 2 0 2 0 2
2 0 2 0 2 0 2 0
1
SAMPLE INPUT
0 1 0 1 0 1 0 1
1 0 1 0 1 0 0 0
0 0 0 0 0 1 0 0
0 0 0 0 2 0 0 0
0 0 0 0 0 0 0 0
0 0 2 0 0 0 0 0
0 0 0 2 0 0 0 2
2 0 2 0 2 0 2 0
1
SAMPLE OUTPUT
2 5
2
4 3
6 1

Explanation

This is player 1’s turn, and the player will move the piece at [2,5] and will make two jumps. First jump will be at [4,3and second jump will be at [6,1]

After his/her move the state of game becomes:

0 1 0 1 0 1 0 1
1 0 1 0 1 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 1 0 2 0 2 0 2
2 0 2 0 2 0 2 0

This state will be fed as input to program of player 2.

Other valid move for the first player is

2 5
1
3 6

But the following are invalid moves.
Case 1:

2 5
1
4 3

Because after making a jump its possible to jump again and its mandatory to jump as long as its possible to jump.

Case 2:

2 5
2
4 3
5 4

Because after making a jump its invalid to move to diagonally adjacent cell.

Here is the code of the Random Bot.

Time Limit:1.0 sec(s) for each input file.
Memory Limit:256 MB
Source Limit:1024 KB

Solution

This is the solution submitted by me



REST Application in Java

Below are the basic steps to create a working REST API Application in java, using Eclipse.
The demo shows just a “To Uppercase String” application

Steps:

  • In Eclipse, create a new Project(Dynamic Web Project)
  • Create the new Project and give it a suitable name.
  • after project creation, right click on the project, and select Configure-> Convert to Maven Project
  • After process completion, a pom.xml would be made available.
  • Add the dependencies from the pom.xml that I have presented below.
  • Create new Class as sample shown below and create methods that you need to expose.
  • Add business logic as per need.
  • Add Annotations to the class as shown below
  • In the Web Content folder, modify the web.xml as shown in the sample web.xml

The basic mode is complete. Now just configure your local web server and deploy your application to the web server.

Use any REST Client like Postman(Chrome Plugin) to test the app.

Code Samples


HackerEarth: Battle Of Bots #5: Reversi

Problem:

Reversi is a two player board game which is played on a 10 x 10 grid of cells. Each player has an allocated color, Black ( First Player ) or White ( Second Player ) being conventional. Players take turns placing a stone of their color on a single cell. A player must place a stone on the board, in such a position that there exists at least one straight (horizontal, vertical, or diagonal) occupied line between the new stone and another stone of same color, with one or more contiguous other color stone between them.

During a game, any stone of the opponent’s color that are in a straight line and bounded by the stone just placed and another stone of the current player’s color are turned over to the current player’s color. The game will end when the board is completely filled or both the players don’t have any move left. At the end of the game the player with majority of stone will win.

We will play it on an 10 x 10 grid. The top left of the grid is [0,0] and the bottom right is [9,9]. The rule is that a cell[i,j] is connected to any of top, left, right, or bottom cell.

Input:
The input will be a 10 x 10 matrix consisting only of 0,1,2 or 3. Then another line will follow which will contain a number – 1 or 2 which is your player id.

In the given matrix, top-left is [0,0] and bottom-right is [9,9].

In cell[row,column], row increases from top to bottom and column increases from left to right.

The cell marked 0 means it doesn’t contain any stones. The cell marked 1 means it contains first player’s stone which is Black in color. The cell marked 2 means it contains second player’s stone which is white in color. The cell marked 3 means it is a valid place for player whose turn it is.

Output:
Print the coordinates of the cell separated by space, where you want to play your move. You must take care that you don’t print invalid coordinates. For example, [1] might be a valid coordinate in the game play if cell[i,j]=3, but [10] will never be. Also if you play an invalid move or your code exceeds the time/memory limit while determining the move, you lose the game.

Starting state
The starting state of the game is the state of the board before the game starts.

0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 2 1 0 0 0 0
0 0 0 0 1 2 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0

First Input
This is the input give to the first player at the start of the game.

0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 3 0 0 0 0 0
0 0 0 3 2 1 0 0 0 0
0 0 0 0 1 2 3 0 0 0
0 0 0 0 0 3 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
1

Scoring
The scores are calculated by running tournament of all submissions. Your latest submission will be taken into tournament. Scores are assigned according to the Glicko-2 rating system. For more information and questions, see Bot problem judge.

SAMPLE INPUT

0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 3 0 0 0 0 0
0 0 0 3 2 1 3 0 0 0
0 0 0 0 2 2 0 0 0 0
0 0 0 3 1 1 2 3 0 0
0 0 0 1 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
1
SAMPLE OUTPUT
4 3

Explanation

This is player 1’s turn, and the player puts his/her stone in cell[4,3].
After his/her move the state of game becomes:

0 0 0 0 0 0 0 0 0 0  
0 0 0 0 0 0 0 0 0 0  
0 0 0 0 0 0 0 0 0 0  
0 0 0 3 0 3 0 0 0 0  
0 0 0 1 1 1 0 0 0 0  
0 0 0 3 1 2 0 0 0 0  
0 0 0 3 1 1 2 0 0 0  
0 0 0 1 0 3 0 0 0 0  
0 0 3 0 0 0 0 0 0 0  
0 0 0 0 0 0 0 0 0 0  

This state will be fed as input to program of player 2.


Time Limit:1.0 sec(s) for each input file.
Memory Limit: 256 MB
Source Limit: 1024 KB
Marking Scheme:Marks are awarded if any testcase passes.
Allowed Languages:C, CPP, CLOJURE, CSHARP, D, ERLANG, FSHARP, GO, GROOVY, HASKELL, JAVA, JAVA8, JAVASCRIPT, JAVASCRIPT_NODE, LISP, LISP_SBCL, LUA, OBJECTIVEC, OCAML, OCTAVE, PASCAL, PERL, PHP, PYTHON, PYTHON3, R, RACKET, RUBY, RUST, SCALA, SWIFT, VB

My Solution:


How to determine which jar a class is loaded from?

When the method that contains this sniplet is called, it will print out something like:

file://path/to/deployment/lib/detected.jar

Will the codeSource be null? The answer is yes. When a jar file is loaded by the system class loader, it’s codeSource will be null. What jars will be loaded by the system class loader? the rule of thumb is that all the jars in the class path (not the ones you package in your application) will be loaded by the system class loader. Obviously the above code can’t used to find out which jar a class is loaded from, if the jar is loaded by the system class loader. You can use the “verbose” java command line argument when you start the application:

java -verbose app

it will print out every class in each jar the system class loader loads, ie:

[Opened C:\dev\bea\JDK160~1\jre\lib\rt.jar]
[Loaded java.lang.Object from C:\dev\bea\JDK160~1\jre\lib\rt.jar]
[Loaded java.io.Serializable from C:\dev\bea\JDK160~1\jre\lib\rt.jar]
[Loaded java.lang.Comparable from C:\dev\bea\JDK160~1\jre\lib\rt.jar]
[Loaded java.lang.CharSequence from C:\dev\bea\JDK160~1\jre\lib\rt.jar]
[Loaded java.lang.String from C:\dev\bea\JDK160~1\jre\lib\rt.jar]
[Loaded java.lang.reflect.GenericDeclaration from C:\dev\bea\JDK160~1\jre\lib\rt.jar]

Source




Apache Solr vs Elasticsearch: The Feature Smackdown

API

Feature Solr 5.3.0 ElasticSearch 2.0
Format XML,CSV,JSON JSON
HTTP REST API
Binary API SolrJ TransportClient, Thrift (through a plugin)
JMX support ES specific stats are exposed through the REST API
Official client libraries Java Java, Groovy, PHP, Ruby, Perl, Python, .NET, JavascriptOfficial list of clients
Community client libraries PHP, Ruby, Perl, Scala, Python, .NET, Javascript, Go, Erlang, Clojure Clojure, Cold Fusion, Erlang, Go, Groovy, Haskell, Java, JavaScript, .NET, OCaml, Perl, PHP, Python, R, Ruby, Scala, Smalltalk, Vert.x Complete list
3rd-party product integration (open-source) Drupal, Magento, Django, ColdFusion, WordPress, OpenCMS, Plone, Typo3, ez Publish, Symfony2, Riak (via Yokozuna) Drupal, Django, Symfony2, WordPress, CouchBase
3rd-party product integration (commercial) DataStax Enterprise Search, Cloudera Search, Hortonworks Data Platform, MapR SearchBlox, Hortonworks Data Platform, MapR etcComplete list
Output JSON, XML, PHP, Python, Ruby, CSV, Velocity, XSLT, native Java JSON, XML/HTML (via plugin)

Infrastructure

Feature Solr 5.3.0 ElasticSearch 2.0
Master-slave replication Only in non-SolrCloud. In SolrCloud, behaves identically to ES. Not an issue because shards are replicated across nodes.
Integrated snapshot and restore Filesystem Filesystem, AWS Cloud Plugin for S3 repositories, HDFS Plugin for Hadoop environments, Azure Cloud Plugin for Azure storage repositories

Indexing

Feature Solr 5.3.0 ElasticSearch 2.0
Data Import DataImportHandler – JDBC, CSV, XML, Tika, URL, Flat File [DEPRECATED in 2.x] Rivers modules – ActiveMQ, Amazon SQS, CouchDB, Dropbox, DynamoDB, FileSystem, Git, GitHub, Hazelcast, JDBC, JMS, Kafka, LDAP, MongoDB, neo4j, OAI, RabbitMQ, Redis, RSS, Sofa, Solr, St9, Subversion, Twitter, Wikipedia
ID field for updates and deduplication
DocValues
Partial Doc Updates with stored fields with _source field
Custom Analyzers and Tokenizers
Per-field analyzer chain
Per-doc/query analyzer chain
Synonyms Supports Solr and Wordnet synonym format
Multiple indexes
Near-Realtime Search/Indexing
Complex documents
Schemaless 4.4+
Multiple document types per schema One set of fields per schema, one schema per core
Online schema changes Schemaless mode or via dynamic fields. Only backward-compatible changes.
Apache Tika integration
Dynamic fields
Field copying via multi-fields
Hash-based deduplication Murmur plugin or ER plugin

Searching

Feature Solr 5.3.0 ElasticSearch 2.0
Lucene Query parsing
Structured Query DSL Need to programmatically create queries if going beyond Lucene query syntax.
Span queries via SOLR-2703
Spatial/geo search
Multi-point spatial search
Faceting Top N term accuracy can be controlled with shard_size
Advanced Faceting New JSON faceting API blog post
Geo-distance Faceting
Pivot Facets
More Like This
Boosting by functions
Boosting using scripting languages
Push Queries JIRA issue Percolation. Distributed percolation supported in 1.0
Field collapsing/Results grouping
Spellcheck Suggest API
Autocomplete
Query elevation workaround
Joins Joined index has to be single-shard and replicated across all nodes. via has_children and top_children queries
Resultset Scrolling New to 4.7.0 via scan search type
Filter queries also supports filtering by native scripts
Filter execution order local params and cache property
Alternative QueryParsers DisMax, eDisMax query_string, dis_max, match, multi_match etc
Negative boosting but awkward. Involves positively boosting the inverse set of negatively-boosted documents.
Search across multiple indexes it can search across multiple compatible collections
Result highlighting
Custom Similarity
Searcher warming on index reload Warmers API
Term Vectors API

Customizability

Feature Solr 5.3.0 ElasticSearch 2.0
Pluggable API endpoints
Pluggable search workflow via SearchComponents
Pluggable update workflow
Pluggable Analyzers/Tokenizers
Pluggable Field Types
Pluggable Function queries
Pluggable scoring scripts
Pluggable hashing
Pluggable webapps site plugin
Automated plugin installation Installable from GitHub, maven, sonatype or elasticsearch.org

 

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