Skip to main content

Day 18: Queues and Stacks Hackerrank Solution Java

 Day 18: Queues and Stacks Hackerrank Solution Java

For Explanation Check Video:


Sample Input

racecar

Sample Output

The word, racecar, is a palindrome.
Code:
import java.io.*;
import java.util.*;

public class Solution {
    // Write your code here.//racecar
    Stack<Character> st = new Stack<>();
    Queue<Character> q = new LinkedList<>();
    void pushCharacter(char ch){
        st.push(ch);//race
    }
    void enqueueCharacter(char ch){
        q.add(ch);//ecar
    }
    char popCharacter(){
        return st.pop();//c
    }
    char dequeueCharacter(){
        return q.remove();//c
    }
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        String input = scan.nextLine();
        scan.close();

        // Convert input String to an array of characters:
        char[] s = input.toCharArray();

        // Create a Solution object:
        Solution p = new Solution();

        // Enqueue/Push all chars to their respective data structures:
        for (char c : s) {
            p.pushCharacter(c);
            p.enqueueCharacter(c);
        }

        // Pop/Dequeue the chars at the head of both data structures and compare them:
        boolean isPalindrome = true;
        for (int i = 0; i < s.length/2; i++) {
            if (p.popCharacter() != p.dequeueCharacter()) {
                isPalindrome = false;                
                break;
            }
        }

        //Finally, print whether string s is palindrome or not.
        System.out.println( "The word, " + input + ", is " 
                           + ( (!isPalindrome) ? "not a palindrome." : "a palindrome." ) );
    }
}

Comments

Popular posts from this blog

Servlet Project Book Shop Application in eclipse

 Servlet Project Book Shop Application in eclipse  For explanation watch video::: Note :: In this Project you must configure web server (for example tomcat) with eclipse ide Download Bootstrap  from ::         https://getbootstrap.com/docs/4.3/getting-started/download/ Download mysql jar file from :: https://mvnrepository.com/artifact/mysql/mysql-connector-java/8.0.22 adding MySQL Connector/J jar file in eclipse ide for jdbc video :: video link : https://youtu.be/4Fyd-k3eG_I Directory Structure:: web.xml <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" id="WebApp_ID" version="4.0">   <welcome-file-list>     <welcome-file>home.html</welcome-file>   </welcome-file-list>   <display-

JDBC basic example For Select Query

JDBC basic example For Select Query  For explanation watch video:  For Creating Table:: SQL> create table emp60(srno int,fname varchar2(10)); Table created. SQL> desc emp60;  Name                                      Null?    Type  ----------------------------------------- -------- ----------------------------  SRNO                                               NUMBER(38)  FNAME                                              VARCHAR2(10) SQL> insert into emp60 values(1,'allu'); 1 row created. SQL> insert into emp60 values(2,'vijay'); 1 row created. SQL> insert into emp60 values(3,'rajni'); 1 row created. SQL> select * from emp60;       SRNO FNAME ---------- ----------          1 allu          2 vijay          3 rajni TO check Service Id: SQL> commit; Commit complete. SQL> select * from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- ORCL JDBC Program:: =========== import java.sql.*;

JDBC Program to access table data from mysql database

 import java.sql.*; class MysqlCon  { public static void main(String[] args)  { try{ Connection con = DriverManager.getConnection("jdbc:mysql:///new","root","root"); Statement st = con.createStatement(); String query = "select * from login"; ResultSet rs = st.executeQuery(query); while(rs.next()){ System.out.println(rs.getString(1)+" "+rs.getString(2)); } con.close(); }catch(SQLException e){ System.out.println("Error"); }catch(Exception e){ } } }