Peter
Peter Campbell Smith

Digits and doubling

Weekly challenge 261 — 18 March 2024

Week 261 - 18 Mar 2024

Task 1

Task — Element digit sum

You are given an array of integers, @ints. Write a script to evaluate the absolute difference between element and digit sum of the given array.

Examples


Example 1
Input: @ints = (1,2,3,45)
Output: 36

Element Sum: 1 + 2 + 3 + 45 = 51
Digit Sum: 1 + 2 + 3 + 4 + 5 = 15
Absolute Difference: | 51 - 15 | = 36

Example 2
Input: @ints = (1,12,3)
Output: 9

Element Sum: 1 + 12 + 3 = 16
Digit Sum: 1 + 1 + 2 + 3 = 7
Absolute Difference: | 16 - 7 | = 9

Example 3
Input: @ints = (1,2,3,4)
Output: 0

Element Sum: 1 + 2 + 3 + 4 = 10
Digit Sum: 1 + 2 + 3 + 4 = 10
Absolute Difference: | 10 - 10 | = 0

Example 4
Input: @ints = (236, 416, 336, 350)
Output: 1296

Analysis

Each of the two required sums is an easy single line in Perl, and the difference a simple subtraction. The 'absolute' in the task description is superfluous, as no positive integer's digit sum can exceed itself.

The task description does not explicitly exclude negative integers, but the examples all use only positive integers, and we would need to be told, for example, whether to treat -45 as - 4 + 5 or - 4 - 5. I have assumed that we are only interested in positive values.

Try it 

Try running the script with any input:



example: 11, 22, 33, 44, 55

Script


#!/usr/bin/perl

# Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge

use v5.26;    # The Weekly Challenge - 2024-03-18
use utf8;     # Week 261 - task 1 - Element digit sum
use warnings; # Peter Campbell Smith
binmode STDOUT, ':utf8';

my (@ints, $j);

element_digit_sum(1, 2, 3, 45);
element_digit_sum(1, 12, 3);
element_digit_sum(1, 2, 3, 4);
element_digit_sum(236, 416, 336, 350);

# longer random example
for $j (0 .. 49) {
    $ints[$j] = int(rand(1000));
}
element_digit_sum(@ints);

sub element_digit_sum {
    
    my (@ints, $digit_sum, $element_sum, $difference);
    
    # calculate sums
    @ints = @_;
    $element_sum += $_ for @ints;
    $digit_sum += $_ for split('', join('', @ints));
    
    # calculate difference
    $difference = abs($element_sum - $digit_sum);
    
    say qq[\nInput:  \@ints = (] . join(', ', @ints) . qq[)\n] .
        qq[Output: $difference (element sum = $element_sum, digit sum = $digit_sum)];
}

Output

	
Input:  @ints = (1, 2, 3, 45)
Output: 36 (element sum = 51, digit sum = 15)

Input:  @ints = (1, 12, 3)
Output: 9 (element sum = 16, digit sum = 7)

Input:  @ints = (1, 2, 3, 4)
Output: 0 (element sum = 10, digit sum = 10)

Input:  @ints = (236, 416, 336, 350)
Output: 1296 (element sum = 1338, digit sum = 42)

Input:  @ints = (498, 749, 269, 81, 991, 111, 388, 595, 450, 358, 632, 135, 343, 378, 512, 394, 855, 474, 197, 352, 962, 686, 930, 26, 799, 179, 141, 837, 779, 612, 714, 658, 40, 206, 330, 881, 67, 506, 113, 543, 281, 229, 252, 475, 165, 763, 61, 238, 30, 775)
Output: 21375 (element sum = 22040, digit sum = 665)
	

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