second.pl

#!/usr/bin/env perl
# for hackerrank https://www.hackerrank.com/challenges/nested-list/problem

# read the input file
@input = <>;

# get the first line; that's the number of students
$count = shift @input;

# process the rest of the input...
foreach (@input) {

    # get rid of the new line
    chomp;

    # if the line is a string, grab it as a name
    if (/^[a-zA-Z]+$/) { $name =$_; next; }

    # if the line is a number, grab is as a score
    if (/^\d+\.?\d+$/) { $score = $_; }

    # create a hash of scores, each one pointing to an
    # array with the students that have that score
    push @{ $scores{$score} }, $name;
}

# sort the scores; the lowest score will be in position 0
# second lowest score will be in position 1
@sorted_scores = sort { $a <=> $b } keys %scores;

# use the second lowest score to index into the hash of scores
# that location has the list of students with that score
# do some funky joining to print each name on a new line
print join( "\n", sort( @{ $scores{ $sorted_scores[1] } } ) ), "\n";