Peter
Peter Campbell Smith

Delete and double

Weekly challenge 235 — 18 September 2023

Week 235 - 18 Sep 2023

Task 2

Task — Duplicate zeroes

You are given an array of integers. Write a script to duplicate each occurrence of ZERO in the given array and shift the remaining to the right but make sure the size of array remain the same.

Examples


Example 1
Input: @ints = (1, 0, 2, 3, 0, 4, 5, 0)
Output: (1, 0, 0, 2, 3, 0, 0, 4)

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

Example 3
Input: @ints = (0, 3, 0, 4, 5)
Output: (0, 0, 3, 0, 0)

Analysis

This was quite easy. Pass along @ints. When you find a non-zero, push it onto @new, or if it is a zero, push two zeroes onto @new. And then truncate @new to be the same length as @ints.

Try it 

Try running the script with any input, for example:
1, 0, 2, 3, 0, 4


Script


#!/usr/bin/perl

use v5.16;    # The Weekly Challenge - 2023-09-18
use utf8;     # Week 235 task 2 - Duplicate zeroes
use strict;   # Peter Campbell Smith
use warnings; # Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge

duplicate_zeroes(1, 0, 2, 3, 0, 4, 5, 0);
duplicate_zeroes(1, 2, 3);
duplicate_zeroes(0, 3, 0, 4, 5);
duplicate_zeroes(0, 0, 0, 0, 1, 2, 3, 4);
duplicate_zeroes(1, 2, 3, 4, 5, 0);

sub duplicate_zeroes {
    
    my (@ints, $j, @new);
    
    # initialise
    @ints = @_;
    
    # push items from @ints onto @new, doubling every 0
    push @new, ($_ == 0 ? (0, 0) : $_) for @ints;
    
    # cut back @new to the length of @ints
    @new = @new[0 .. scalar @ints - 1];
    
    # show results
    say qq[\nInput:  \@ints = (] . join(qq[, ], @ints) . q[)];
    say qq[Output:         (] . join(qq[, ], @new) . q[)];;
}

Output


Input:  @ints = (1, 0, 2, 3, 0, 4, 5, 0)
Output:         (1, 0, 0, 2, 3, 0, 0, 4)

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

Input:  @ints = (0, 3, 0, 4, 5)
Output:         (0, 0, 3, 0, 0)

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

Input:  @ints = (1, 2, 3, 4, 5, 0)
Output:         (1, 2, 3, 4, 5, 0)

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