Solutions to challenge-098.

3 files changed, 110 insertions, 0 deletions

diff --git a/challenge-098/wanderdoc/perl/ch-1.pl b/challenge-098/wanderdoc/perl/ch-1.pl
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+++ b/challenge-098/wanderdoc/perl/ch-1.pl
@@ -0,0 +1,37 @@
+#!perl
+use strict;
+use warnings FATAL => qw(all);
+
+=prompt
+You are given file $FILE. Create subroutine readN($FILE, $number) returns the first n-characters and moves the pointer to the (n+1)th character.
+Example:
+Input: Suppose the file (input.txt) contains "1234567890"
+Output:
+    print readN("input.txt", 4); # returns "1234"
+    print readN("input.txt", 4); # returns "5678"
+    print readN("input.txt", 4); # returns "90"
+
+=cut
+
+
+
+
+
+
+use FindBin qw($Bin); # Windows.
+use IO::File; 
+use feature 'state';
+
+
+
+sub readN
+{
+     my ($file, $num) = @_;
+     state $handle = (IO::File->new("$Bin/$file", "r") or die "$!");
+     my $into;
+     read($handle, $into, $num);
+     return $into;
+}
+print readN("input.txt", 4), $/; # 1234
+print readN("input.txt", 4), $/; # 5678
+print readN("input.txt", 4), $/; # 90
\ No newline at end of file
diff --git a/challenge-098/wanderdoc/perl/ch-2.pl b/challenge-098/wanderdoc/perl/ch-2.pl
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+++ b/challenge-098/wanderdoc/perl/ch-2.pl
@@ -0,0 +1,72 @@
+#!perl
+use strict;
+use warnings FATAL => qw(all);
+
+=prompt
+You are given a sorted array of distinct integers @N and a target $N. Write a script to return the index of the given target if found otherwise place the target in the sorted array and return the index.
+Example 1:
+
+Input: @N = (1, 2, 3, 4) and $N = 3
+Output: 2 since the target 3 is in the array at the index 2.
+
+Example 2:
+
+Input: @N = (1, 3, 5, 7) and $N = 6
+Output: 3 since the target 6 is missing and should be placed at the index 3.
+
+Example 3:
+
+Input: @N = (12, 14, 16, 18) and $N = 10
+Output: 0 since the target 10 is missing and should be placed at the index 0.
+
+Example 4:
+
+Input: @N = (11, 13, 15, 17) and $N = 19
+Output: 4 since the target 19 is missing and should be placed at the index 4.
+
+=cut
+
+use List::Util qw(first);
+
+# Actually we have to return index only, thus:
+
+sub return_idx
+{
+     my ($aref, $num) = @_;
+     my %idx;
+     @idx{@$aref} = keys @$aref;
+     return $idx{$num} if exists $idx{$num};
+
+
+     my $neighbour = first { $_ > $num } @$aref;
+     my $should_be_placed = $neighbour ? $idx{$neighbour} : scalar @$aref;
+     return $should_be_placed;
+}
+
+print return_idx([1, 2, 3, 4], 3), $/; # 2
+print return_idx([1, 3, 5, 7], 6), $/; # 3
+
+
+print return_idx([12, 14, 16, 18], 10), $/; # 0
+print return_idx([11, 13, 15, 17], 19), $/, $/; # 4
+
+# If we do have to modify the array:
+
+sub search_insert
+{
+     my ($aref, $num) = @_;
+
+     my %idx;
+     @idx{@$aref} = keys @$aref;
+     return $idx{$num} if exists $idx{$num};
+     @$aref = sort {$a <=> $b} @$aref, $num;
+     @idx{@$aref} = keys @$aref;
+     return $idx{$num};
+}
+
+
+print search_insert([1, 2, 3, 4], 3), $/; # 2
+print search_insert([1, 3, 5, 7], 6), $/; # 3
+
+print search_insert([12, 14, 16, 18], 10), $/; # 0
+print search_insert([11, 13, 15, 17], 19), $/; # 4
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diff --git a/challenge-098/wanderdoc/perl/input.txt b/challenge-098/wanderdoc/perl/input.txt
new file mode 100644
index 0000000000..6a537b5b36
--- /dev/null
+++ b/challenge-098/wanderdoc/perl/input.txt
@@ -0,0 +1 @@
+1234567890
\ No newline at end of file