That One Is Mine: The (Perl and JS) Weekly Challenge #126
TASK #1 › Count Numbers
Submitted by: Mohammad S Anwar
You are given a positive integer $N.Write a script to print count of numbers from 1 to $N that don’t contain digit 1.
There are two things we need for this: a range of numbers from 2 to $N (because why include 1 if it’s just always going to be excluded?) and a filter to knock out the 1s.
In perl, range is 2 .. $n and the filter is grep { ! /1/ }, which makes this quite close to a one-liner. I mean yes, it can be as simple as ` perl -e ‘print join “ “, grep {!/1/} 2..60’`, but I don’t like writing command-line Perl.
With Node, the range part is harder: let array = Array(n).fill().map((x, i) => i + 1). This brings in the unnecessary 1. If I was more clever, I would work around it, but I dunno, I don’t think that adding clever to this problem does more than obfuscate things.
For filtering, we actually get filter. In this case, we go through the list, converting every value to string because 1 doesn’t exist until you take it out of integer and put a base on it, then filter for that 1.
It’s ! x.toString().match(/1/) and not x.toString().match(!/1/) because we want to exclude ones, not see if there’s any number but one.
Show Me The Code!
#!/usr/bin/env perl
use strict ;
use warnings ;
use feature qw{ say postderef signatures state } ;
no warnings qw{ experimental } ;
use Carp;
use Getopt::Long;
my $n = 15;
GetOptions(
'n=i' => \$n
);
croak 'Out of Range!' if $n < 1;
say join ', ' , dont_contain( $n );
sub dont_contain ($n ) {
return grep { ! /1/ } 1 .. $n
}
"use strict";
let n = 126;
let list = Array(n)
.fill()
.map((x, i) => i + 1)
.filter((x) => !x.toString().match(/1/));
console.log(list.join(", "));
TASK #2 › Minesweeper Game
Submitted by: Cheok-Yin Fung
You are given a rectangle with points marked with either x or *. Please consider the x as a land mine.Write a script to print a rectangle with numbers and x as in the Minesweeper game.
A number in a square of the minesweeper game indicates the number of mines within the neighbouring squares (usually 8), also implies that there are no bombs on that square.
Once you get it into a multidimensional array, it’s fairly easy. Go to each mine, circle around it, and if those cells are 1) in the multidimensional array and 2) not actual mines themselves, they get iterated.
I think the clever and useful bit is getting the minefield into the multidimensional array. With Perl, split and map an END block. There are lots of languages, including JS and Python, which I wish had END blocks. With JS, the trick I use is to put it into a comment in an anonymous function, cast the function to string, then split up that string. It’s hackish, but it works.
I’ll say that, while there is much in JS to love, I often find myself missing COMMAND if logic, like next if $xx < 0 and the like. But I make it work.
Show Me The Code!
#!/usr/bin/env perl
use strict ;
use warnings ;
use feature qw{ say postderef signatures state } ;
no warnings qw{ experimental } ;
use JSON ;
my $json = JSON->new->space_after->utf8 ;
my $field = <<END;
x * * * x * x x x x
* * * * * * * * * x
* * * * x * x * x *
* * * x x * * * * *
x * * * x * * * * x
END
my @field = map { [ split /\s/, $_ ] }
split /\n/, $field ;
my $h = -1 + scalar @field ;
my $w = -1 + scalar $field[ 0 ]->@* ;
my @map ;
for my $i ( 0 .. $h ) {
for my $j ( 0 .. $w ) {
$map[ $i ][ $j ] = $field[ $i ][ $j ] eq 'x' ? 'x' : 0 ;
}
}
for my $i ( 0 .. $h ) {
for my $j ( 0 .. $w ) {
next unless $map[ $i ][ $j ] eq 'x' ;
for my $x ( -1 .. 1 ) {
for my $y ( -1 .. 1 ) {
my $xx = $i + $x ;
my $yy = $j + $y ;
next if $xx == 0 && $yy == 0 ;
next if $xx < 0 ;
next if $yy < 0 ;
next if $xx > $h ;
next if $yy > $w ;
next if $map[ $xx ][ $yy ] eq 'x' ;
$map[ $xx ][ $yy ]++ ;
}
}
}
}
show_map( \@map ) ;
sub show_map ( $ref ) {
say '-' x 20 ;
say join "\n", map { join ' ', $_->@* } $ref->@* ;
say '-' x 20 ;
say '' ;
}
"use strict";
let minemap = [];
let field = function () {
/*
x * * * x * x x x x
* * * * * * * * * x
* * * * x * x * x *
* * * x x * * * * *
x * * * x * * * * x
*/
}
.toString()
.split(/\/\*/)[1]
.split(/\*\//)[0]
.split(/\n/)
.filter((x) => String(x).match(/\w/));
let maxx = 0;
let maxy = 0;
for (let x in field) {
maxx = x;
let rowstr = field[x];
let row = rowstr.split(/\s+/g);
minemap[x] = new Array(row.length);
for (let y in row) {
maxy = y;
minemap[x][y] = "0";
if (row[y] === "x") {
minemap[x][y] = "x";
}
}
}
for (let x = 0; x <= maxx; x++) {
for (let y = 0; y <= maxy; y++) {
if (minemap[x][y] === "x") {
for (let i = -1; i <= 1; i++) {
for (let j = -1; j <= 1; j++) {
if (!(i == 0 && i == j)) {
let xx = x + i;
let yy = y + j;
if (xx >= 0 && yy >= 0 && xx <= maxx && yy <= maxy) {
if (minemap[xx][yy] != "x") {
minemap[xx][yy]++;
}
}
}
}
}
}
}
}
for (let x = 0; x <= maxx; x++) {
console.log(minemap[x].join(" "));
}