Dot product

You are given 2 arrays of same size, @a and @b. Write a script to implement Dot Product.

Examples

Example 1:
@a = (1, 2, 3);
@b = (4, 5, 6);
$dot_product = (1 * 4) + (2 * 5) + (3 * 6) => 
   4 + 10 + 18 => 32

Analysis

This could be a one-liner, but for safety I check that the arrays are the same length, and then format the output to match Mohammad's example.

Cool use of regex to find Palindromes. Thanks for sharing your knowledge with us.

Try it 

#!/usr/bin/perl

# Peter Campbell Smith - 2021-12-27
# PWC 145 task 1

use v5.20;
use warnings;
use strict;

my (@tests, $test, @a, @b, $j, $p, $dp, $string1, $string2);

@tests = ([[1, 2, 3], [4, 5, 6]], [[93, 72, 11], [-1, 1000, 0]], [[1, 2, 3, 4], [1, 2, 3]]);

for $test (@tests) {
    
    # extract arrays
    @a = @{$test->[0]};
    @b = @{$test->[1]};
    say qq[\n\@a = (] . join(', ', @a) . qq[)];
    say qq[\@b = (] . join(', ', @b) . qq[)];
    
    # check lengths
    if (scalar @a != scalar @b) {
        say 'Not the same length';
        next;
    }
    
    # make dot product and required output text
    $string1 = $string2 = '';
    $dp = 0;
    for $j (0 .. scalar @a - 1) {
        $p = $a[$j] * $b[$j];
        $dp += $p;
        $string1 .= qq[($a[$j] * $b[$j]) + ];
        $string2 .= qq[$p + ];
    }
    
    say '$dot_product = ' . substr($string1, 0, -2) . '=> ' . substr($string2, 0, -2) . qq[=> $dp];
        
}   
    

21 lines of code

Output from script

@a = (1, 2, 3)
@b = (4, 5, 6)
$dot_product = (1 * 4) + (2 * 5) + (3 * 6) => 4 + 10 + 18 => 32

@a = (93, 72, 11)
@b = (-1, 1000, 0)
$dot_product = (93 * -1) + (72 * 1000) + (11 * 0) => -93 + 72000 + 0 => 71907

@a = (1, 2, 3, 4)
@b = (1, 2, 3)
Not the same length