Day 28: HackerRank 30 Days Of Code Solution by CodingHumans | RegEx, Patterns, and Intro to Databases |

Day 28: RegEx, Patterns, and Intro to Databases

Objective

Hey Today, we're working with regular expressions.

Task

Consider a database table, Emails, which has the attributes First Name and Email ID. Given N rows of data simulating the Emails table, print an alphabetically-ordered list of people whose email address ends in @gmail.com .

Input Style

The first line contains an integer, N, total number of rows in the table.
Each of the N subsequent lines contains 2 space-separated strings denoting a person's first name and email ID, respectively.

Constraints

2<= N <= 30

Each of the first names consists of lower case letters [a-z] only.

Each of the email IDs consists of lower case letters , [a-z], @ and .  only.

The length of the first name is no longer than 20.

The length of the email ID is no longer than 50.

Output Style

Print an alphabetically-ordered list of first names for every user with a gmail account. Each name must be printed on a new line.

Sample Input

6
riya riya@gmail.com
julia julia@julia.me
julia sjulia@gmail.com
julia julia@gmail.com
samantha samantha@gmail.com
tanya tanya@gmail.com
Sample Output

julia
julia
riya
samantha
tanya

Recommended: Please try your approach on your integrated development environment (IDE) first, before moving on to the solution.

Few words from CodingHumans : Don't Just copy paste the solution, try to analyze the problem and solve it without looking by taking the the solution as a hint or a reference . Your understanding of the solution matters.

HAPPY CODING 😁

Solution
( Java )

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        String Regrex=".+@gmail\\.com$";
        List<String> list= new ArrayList();
        Pattern pattern=Pattern.compile(Regrex);
        for(int i=0;i<n;i++){
            String name=scanner.next();
            String email=scanner.next();
            Matcher matcher=pattern.matcher(email);
            if(matcher.find()){
                list.add(name);
            }
        }
        Collections.sort(list);
        for(String names:list){
            System.out.println(names);
        }
        scanner.close();
    }
}

If you have any doubts regarding this problem or  need the solution in other programming languages then leave a comment down below .