Day 28: RegEx, Patterns, and Intro to Databases

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

Input Format

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

Constraints

• Each of the first names consists of lower case letters  only.
• Each of the email IDs consists of lower case letters ,  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 Format

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

풀이

package Day28;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int N = in.nextInt();
        List<String> strings = new ArrayList<>();
        for(int a0 = 0; a0 < N; a0++){
            String firstName = in.next();
            String emailID = in.next();
            if (emailID.contains("@gmail.com"))  strings.add(firstName);
        }

        Collections.sort(strings);
        for (String str : strings)
            System.out.println(str);
    }
}