AWK solution for week 102, part 2

2 files changed, 37 insertions, 0 deletions

diff --git a/challenge-102/abigail/README.md b/challenge-102/abigail/README.md
index 4bd71dcf9b..33608bff29 100644
--- a/challenge-102/abigail/README.md
+++ b/challenge-102/abigail/README.md
@@ -85,4 +85,5 @@ such length-`N` string.
 ~~~~
 
 ### Solutions
+* [AWK](awk/ch-2.awk)
 * [Perl](perl/ch-2.pl)
diff --git a/challenge-102/abigail/awk/ch-2.awk b/challenge-102/abigail/awk/ch-2.awk
new file mode 100644
index 0000000000..e673437860
--- /dev/null
+++ b/challenge-102/abigail/awk/ch-2.awk
@@ -0,0 +1,36 @@
+#!/usr/bin/awk
+
+#
+# See ../README.md
+#
+
+#
+# Run as: awk -f ch-2.awk < input-file
+#
+
+#
+# Working from the end of the required string backwards, we alternate
+# placing a hash, and placing a number. We place them in an array out,
+# and at the end, print out said array in reverse order.
+#
+
+{
+    idx  = $1
+    hash = 0
+    i    = 0
+    while (idx) {
+        i ++
+        if (hash = !hash) {
+            out [i] = "#"
+            idx --
+        }
+        else {
+            out [i] =       idx + 1
+            idx  -= length (idx + 1)
+        }
+    }
+    for (; i; i --) {
+        printf "%s", out [i]
+    }
+    printf "\n"
+}