First set of solutions for week 131.

Part 1: AWK, C, Perl.
Part 2: AWK, Perl.

6 files changed, 171 insertions, 0 deletions

diff --git a/challenge-131/abigail/README.md b/challenge-131/abigail/README.md
index 38e51d0b9c..4c27485f4c 100644
--- a/challenge-131/abigail/README.md
+++ b/challenge-131/abigail/README.md
@@ -1 +1,12 @@
 # Solutions by Abigail
+
+## Part 1
+
+* [AWK](awk/ch-1.awk)
+* [C](c/ch-1.c)
+* [Perl](perl/ch-1.pl)
+
+## Part 2
+
+* [AWK](awk/ch-2.awk)
+* [Perl](perl/ch-2.pl)
diff --git a/challenge-131/abigail/awk/ch-1.awk b/challenge-131/abigail/awk/ch-1.awk
new file mode 100644
index 0000000000..bdf93e5a1a
--- /dev/null
+++ b/challenge-131/abigail/awk/ch-1.awk
@@ -0,0 +1,18 @@
+#!/usr/bin/awk
+
+#
+# See ../README.md
+#
+
+#
+# Run as: awk -f ch-1.awk < input-file
+#
+
+{
+    prev = 0
+    for (i = 1; i <= NF; i ++) {
+        printf ("%s%d", prev == 0 ? "" : (prev + 1 == $i) ? " " : "\n",
+                       (prev = $i))
+    }
+    printf ("\n")
+}
diff --git a/challenge-131/abigail/awk/ch-2.awk b/challenge-131/abigail/awk/ch-2.awk
new file mode 100644
index 0000000000..5215d94acf
--- /dev/null
+++ b/challenge-131/abigail/awk/ch-2.awk
@@ -0,0 +1,35 @@
+#!/usr/bin/awk
+
+#
+# See ../README.md
+#
+
+#
+# Run as: awk -f ch-2.awk < input-file
+#
+
+NR == 1 {
+    n = split ($0, delims, "")
+}
+
+NR == 2 {
+    m = split ($0, chars, "")
+    out1 = ""
+    out2 = ""
+    for (i = 1; i <= m; i ++) {
+        for (j = 1; j <= n; j += 2) {
+            if (delims [j] == chars [i]) {
+                out1 = out1 delims [j]
+                break
+            }
+        }
+        for (j = 2; j <= n; j += 2) {
+            if (delims [j] == chars [i]) {
+                out2 = out2 delims [j]
+                break
+            }
+        }
+    }
+    print out1
+    print out2
+}
diff --git a/challenge-131/abigail/c/ch-1.c b/challenge-131/abigail/c/ch-1.c
new file mode 100644
index 0000000000..783d0f19d3
--- /dev/null
+++ b/challenge-131/abigail/c/ch-1.c
@@ -0,0 +1,35 @@
+# include <stdlib.h>
+# include <stdio.h>
+# include <string.h>
+
+/*
+ * See ../README.md
+ */
+
+/*
+ * Run as: cc -o ch-1.o ch-1.c; ./ch-1.o < input-file
+ */
+
+int main (void) {
+    char *  line    = NULL;
+    size_t  len     = 0;
+    size_t  str_len;
+
+    while ((str_len = getline (&line, &len, stdin)) != -1) {
+        char * line_ptr = line;
+        int num;
+        int offset;
+        int prev = 0;
+        while (sscanf (line_ptr, "%d%n", &num, &offset) == 1) {
+            printf ("%s%d", prev     == 0   ? ""
+                          : prev + 1 == num ? " "
+                          :                   "\n", num);
+            prev = num;
+            line_ptr += offset;
+        }
+        printf ("\n");
+    }
+    free (line);
+
+    return (0);
+}
diff --git a/challenge-131/abigail/perl/ch-1.pl b/challenge-131/abigail/perl/ch-1.pl
new file mode 100644
index 0000000000..413c037a86
--- /dev/null
+++ b/challenge-131/abigail/perl/ch-1.pl
@@ -0,0 +1,24 @@
+#!/opt/perl/bin/perl
+
+use 5.032;
+
+use strict;
+use warnings;
+no  warnings 'syntax';
+
+use experimental 'signatures';
+use experimental 'lexical_subs';
+
+#
+# See ../README.md
+#
+
+#
+# Run as: perl ch-1.pl < input-file
+#
+
+while (<>) {
+    my $prev = 0;
+    print $prev ? $prev + 1 == $_ ? " " : "\n" : "", $prev = $_ for /[0-9]+/g;
+    print "\n";
+}
diff --git a/challenge-131/abigail/perl/ch-2.pl b/challenge-131/abigail/perl/ch-2.pl
new file mode 100644
index 0000000000..03fba700d3
--- /dev/null
+++ b/challenge-131/abigail/perl/ch-2.pl
@@ -0,0 +1,48 @@
+#!/opt/perl/bin/perl
+
+use 5.032;
+
+use strict;
+use warnings;
+no  warnings 'syntax';
+
+use experimental 'signatures';
+use experimental 'lexical_subs';
+
+#
+# See ../README.md
+#
+
+#
+# Run as: perl ch-2.pl < input-file
+#
+# First line of input: delimiters
+# Second line of input: string to search
+#
+
+#
+# What a strange way of phrasing the exercise. We're given a string
+# of "delimiter pairs", but we actually have to do nothing at all with
+# the "delimiter" part.
+#
+# Basically, we have two sets of characters which we need to extract
+# from the string, but for some reason, the two sets of characters
+# are interleaved. Weird.
+#
+
+chomp (my $chars = <>);
+$_ = <>; # String to search
+
+#
+# Extract the characters on the odd and even positions;
+# replace / with \/.
+#
+my $odds = $chars =~ s/(.)./$1/gr =~ s!/!\\/!r;
+my $even = $chars =~ s/.(.)/$1/gr =~ s!/!\\/!r;
+
+#
+# Use y///dc to get rid of the characters which don't match, and
+# print the remainder.
+# 
+say eval "y/$odds//dcr";
+say eval "y/$even//dcr";