# 2020 AoC Day 15 – Rambunctious Recitation

This is a solution to Advent of Code 2020 day 15, written in Raku.

### Part One

Given your starting numbers, what will be the 2020th number spoken?

#### Raku

This a quick-n-dirty solution in Raku. I nearly messed up pushing the last starting input to the %seen list before considering it.

  my @input = 2, 1, 10, 11, 0, 6;

my %seen;
my $last = @input.pop; for ^@input.elems ->$i {
%seen{@input[$i]} =$i;
}

for @input.elems..^2019 -> $i { my$new;
if %seen{$last}:exists {$new = $i - %seen{$last};
} else {
$new = 0; } %seen{$last} = $i;$last = $new; } say$last;
232


### Part Two

Given your starting numbers, what will be the 30000000th number spoken?

#### Raku

The solution to part one was efficient enough that it worked for part two as well. A bit slow to run but manageable.

  my @input = 2, 1, 10, 11, 0, 6;

my %seen;
my $last = @input.pop; for ^@input.elems ->$i {
%seen{@input[$i]} =$i;
}

for @input.elems..^(30000000-1) -> $i { my$new;
if %seen{$last}:exists {$new = $i - %seen{$last};
} else {
$new = 0; } %seen{$last} = $i;$last = $new; } say$last;
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