How to find Intersection of Two Sets in Perl - Step by Step Examples

How to find Intersection of Two Sets in Perl ?

Answer

In Perl, you can find the intersection of two sets using the built-in hash data structure and the keys function to extract the common elements.

✐ Examples

1 Find Intersection of Two Sets

In this example,

We create two hash structures, %set1 and %set2, representing the two sets.
We use the keys function to extract the keys (elements) from %set1 and %set2.
We use the grep function to filter out elements from %set1 that are present in %set2.
The result is an array containing the elements common to both sets.

Perl Program

my %set1 = map { $_ => 1 } qw(1 2 3 4);
my %set2 = map { $_ => 1 } qw(3 4 5 6);

my @intersection = grep { $set2{$_} } keys %set1;

print "Intersection of set1 and set2: @intersection\n";

Output

Intersection of set1 and set2: 3 4

2 Find Intersection of Two Sets with Duplicate Elements

In this example,

We create two hash structures, %set1 and %set2, representing the two sets.
We use the keys function to extract the keys (elements) from %set1 and %set2.
We use the grep function to filter out elements from %set1 that are present in %set2.
The result is an array containing the elements common to both sets, including duplicates.

Perl Program

my %set1 = map { $_ => 1 } qw(1 2 2 3 4);
my %set2 = map { $_ => 1 } qw(2 2 3 4 5);

my @intersection = grep { $set2{$_} } keys %set1;

print "Intersection of set1 and set2 with duplicates: @intersection\n";

Output

Intersection of set1 and set2 with duplicates: 2 2 3 4

Summary

In this tutorial, we learned How to find Intersection of Two Sets in Perl language with well detailed examples.

◀ Previous Next ▶