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Amazon Interview Question for Software Engineer in Tests






Comment hidden because of low score. Click to expand.
2
of 2 vote

## In above example .. searching for key 'Words'
SearchKey(\%hash,'Words'); #SearchKey Funct Pass hashRef and key to be searched

sub SearchKey
{
        my $href = shift;
        my $string = shift;

        my $value = hashTraverse($href,$string);
        print "\n $string === $value\n\n";
}

sub hashTraverse
{
        my $href = shift;
        my $key = shift;
        my $value = $href->{$key};
        my $ref = ref($value);

        if($ref eq "" and defined $value and $value ne "")
        {
                return $value;
        }
        else
        {
                foreach my $tmp(keys %$href)
                {
                        if((ref($href->{$tmp}) eq 'HASH' or ref($href->{$tmp}) eq 'ARRAY') and $tmp eq $key)
                        {
                                print "\nValue reference ",$href->{$tmp},"\n";
                                print Dumper($href->{$tmp});
                                exit 0;
                        }
                        elsif(ref($href->{$tmp}) eq 'HASH')
                        {
                                my $gotit = hashTraverse($href->{$tmp},$key);
                                return $gotit;
                        }
                        elsif(ref($href->{$tmp}) eq 'ARRAY')
                        {
                                my $new = $href->{$tmp};
                                my $index = 0;
                                foreach my $element(@$new)
                                {
                                        my $type = ref($element);
                                        if($element eq $key)
                                        {
                                                print "\n Array Element $element \n\n";
                                                exit 0;
                                        }
                                        if($type eq 'HASH')
                                        {
                                                my $gotit = hashTraverse($href->{$tmp}->[$index],$key);
                                                return $gotit if($gotit ne "");
                                        }
                                        $index++;
                                }
                        }
                }
        }
}

- Abhishek May 21, 2010 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

seems like JSON format ... If we can find grammar for this we can evaluate the expression

- Anonymous May 20, 2010 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

use Data::Dumper;

%h = (a=>0,b=>1,c=>[{'one'=>1,'two'=>2},{1=>'one',2=>'two'},{'number'=>'decimals'},{3 =>'alphas'},'sample']);
%hash = ('abc'=>[123,456,789],'pqr'=>345,'xyz'=>567,'opq'=>'word','lmn'=>\%h,'hello'=>{'zhang'=>'yixing','michael'=>'zhang'});

while($input = <STDIN>) {
chomp($input);
print search(\%hash,$input);
print "\n";
}

sub search {
my $dataRef = shift;
my $key = shift;
if(exists $dataRef->{$key}) {
return $dataRef->{$key};
}
foreach $temp (keys %$dataRef) {
if(ref($dataRef->{$temp}) eq 'HASH') {
$temp = search($dataRef->{$temp},$key);
if($temp) {
return $temp;
}else {
next;
}
}if(ref($dataRef->{$temp}) eq 'ARRAY') {
return searchArray($dataRef->{$temp},$key);
}
}
}

sub searchArray {
my $dataRef = shift;
my $key = shift;
foreach my $element (@$dataRef) {
if(ref($element) eq 'ARRAY') {
return searchArray($element, $key);
}if(ref($element) eq 'HASH') {
$temp = search($element,$key);
if($temp) {
return $temp;
}else {
next;
}
}
}
}

- Michael February 20, 2012 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

use Data::Dumper;

%h = (a=>0,b=>1,c=>[{'one'=>1,'two'=>2},{1=>'one',2=>'two'},{'number'=>'decimals'},{3 =>'alphas'},'sample']);
%hash = ('abc'=>[123,456,789],'pqr'=>345,'xyz'=>567,'opq'=>'word','lmn'=>\%h,'hello'=>{'zhang'=>'yixing','michael'=>'zhang'});

while($input = <STDIN>) {
chomp($input);
print search(\%hash,$input);
print "\n";
}

sub search {
my $dataRef = shift;
my $key = shift;
if(exists $dataRef->{$key}) {
return $dataRef->{$key};
}
foreach $temp (keys %$dataRef) {
if(ref($dataRef->{$temp}) eq 'HASH') {
$temp = search($dataRef->{$temp},$key);
if($temp) {
return $temp;
}else {
next;
}
}if(ref($dataRef->{$temp}) eq 'ARRAY') {
return searchArray($dataRef->{$temp},$key);
}
}
}

sub searchArray {
my $dataRef = shift;
my $key = shift;
foreach my $element (@$dataRef) {
if(ref($element) eq 'ARRAY') {
return searchArray($element, $key);
}if(ref($element) eq 'HASH') {
$temp = search($element,$key);
if($temp) {
return $temp;
}else {
next;
}
}
}
}

- Michael February 20, 2012 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

##################################################
# Function IsArray                               #
# Input: reference                               #
# Output: 1 iff input is a reference to an array #
##################################################
sub IsArray{
   if(ref($_[0]) eq 'ARRAY'){
	   1;
   }else{
		0;
   }
}

##################################################
# Function IsHash                                #
# Input: reference                               #
# Output: 1 iff input is a reference to a Hash   #
##################################################
sub IsHash{
#print "DEBUG-------->",ref($_[0]),"\n";
   if(ref($_[0]) eq 'HASH'){
	   1;
   }else{
		0;
   }
}

##################################################
# Function Search                                #
# Input: nested hash , key                       #
# Output: If key exists in the hash at any level,#
#         output the value, otherwise undef      #
# Algorithm: Recursively go on the values of the #
#            input hash / array.                 #
##################################################
sub Search{
	my ($hashRef , $key ) = @_;

	# print "DEBUG2 ----> Seaching for $key\n";

	# Input is a hash - check for the key, and if not go through the other values
	if (IsHash($hashRef)) {
		if (exists($$hashRef{$key})) {
			return ($$hashRef{$key});
		}

		# Recursively go through the values of the hash
		for (values %$hashRef) {
			if (IsArray($_) or IsHash($_)) {
				my $temp = Search($_,$key);
				if (defined $temp) {
					return $temp
				}
			}
		}
	}

	if (IsArray($hashRef)) {
		# Recursively go through the values of the array
		for (@$hashRef) {
			if (IsArray($_) or IsHash($_)) {
				my $temp = Search($_,$key);
				if (defined $temp) {
					return $temp
				}
			}
		}
	}

	return undef;
}

- leofer October 22, 2012 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

One recursive function:

sub search {
    my ($hashref, $search_key) = @_;
    my $ret_val = undef;
    return $ret_val if ref($hashref) ne 'HASH';
    while ( my ($key, $val) = each %$hashref) {
        if ($key eq $search_key) {
            return $val;
        } elsif (ref($val) eq 'HASH') {
            $ret_val = search($val, $search_key);
        } elsif (ref($val) eq 'ARRAY') {
            foreach my $h (grep {ref($_) eq 'HASH'} @$val) {
                $ret_val = search($h, $search_key);
            }
        }
    }
    return $ret_val;
}

- Anonymous February 15, 2013 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

# Recursion makes the solution easy
sub search_hash {
my $hash_ref = shift;
my $search_key = shift;
foreach my $key (keys %$hash_ref) {
if ($key eq $search_key) {
if (ref($hash_ref->{$key}) eq 'ARRAY') {
print Dumper($hash_ref->{$key});
return;
}
elsif (ref($hash_ref->{$key}) eq 'HASH') {
print Dumper($hash_ref->{$key});
return;
}
elsif (ref($hash_ref->{$key}) eq '') {
print $hash_ref->{$key};
return;
}
}
elsif (ref($hash_ref->{$key}) eq 'HASH') {
search_hash($hash_ref->{$key}, $search_key);
}
elsif (ref($hash_ref->{$key}) eq 'ARRAY') {
search_array($hash_ref->{$key}, $search_key);
}
}
}

sub search_array {
my $arr_ref = shift;
my $search_key = shift;
foreach my $elem (@$arr_ref) {
if (ref($elem) eq 'HASH') {
search_hash($elem, $search_key);
}
if (ref($elem) eq 'ARRAY') {
search_array($elem, $search_key);
}
}
}

- venkibs.eng August 27, 2013 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

sub search {
	
	my $hash_ref = shift;
	my $srch_key = shift;
	
	foreach my $key ( keys(%{$hash_ref}) ) {
		
		if( $key eq $srch_key ) {
			print "\nFound! " . $hash_ref->{$key};
			return $hash_ref->{$key};
			
		} else {
			print "\nref $key == ". ref($hash_ref->{$key});
			if( ref($hash_ref->{$key}) =~ /HASH/ ) {
				
				return search($hash_ref->{$key},$srch_key);
				
			} elsif( ref($hash_ref->{$key}) =~ /ARRAY/ ) {
				
				my @array = @{$hash_ref->{$key}};
				foreach my $element ( @array) {
					
					if( ref($element) =~/HASH/ ) {
						my $val = search($element, $srch_key);
						return $val unless $val == '';
					}
				}
			}
		}			
	}

} # end sub search

- D October 31, 2013 | Flag Reply


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