Task — 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.

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];
        
}   
    

Output

@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