R solution for week 135, part 2

2 files changed, 37 insertions, 0 deletions

diff --git a/challenge-135/abigail/README.md b/challenge-135/abigail/README.md
index 8d165353e3..c6b1e98bb6 100644
--- a/challenge-135/abigail/README.md
+++ b/challenge-135/abigail/README.md
@@ -28,6 +28,7 @@
 * [Node.js](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
 * [Python](python/ch-2.py)
+* [R](r/ch-2.r)
 * [Ruby](ruby/ch-2.rb)
 * [Scheme](scheme/ch-2.scm)
 * [Tcl](tcl/ch-2.tcl)
diff --git a/challenge-135/abigail/r/ch-2.r b/challenge-135/abigail/r/ch-2.r
new file mode 100644
index 0000000000..611ca95bce
--- /dev/null
+++ b/challenge-135/abigail/r/ch-2.r
@@ -0,0 +1,36 @@
+#
+# See ../README.md
+#
+
+#
+# Run as: Rscript ch-2.r < input-file
+#
+
+ord.0 <- as.integer (charToRaw ("0"))
+ord.9 <- as.integer (charToRaw ("9"))
+ord.A <- as.integer (charToRaw ("A"))
+w     <- c (1, 3, 1, 7, 3, 9, 1)
+
+stdin <- file ('stdin', 'r')
+repeat {
+    n <- readLines (stdin, n = 1)
+    if (length (n) == 0) {
+        break
+    }
+    valid <- 1
+    c <- grep ("^[0-9BCDFGHJKLMNPQRSTVWXYZ]{6}[0-9]$", n)
+    if (length (c) == 0) {
+        cat ("0\n")
+        next
+    }
+
+    check <- 0
+    index <- 0
+    for (char in strsplit (n, split = "") [[1]]) {
+        a <- as.integer (charToRaw (char))
+        a <- a - (if (a <= ord.9) ord.0 else ord.A)
+        index <- index + 1
+        check <- check + a * w [index]
+    }
+    cat (if (check %% 10 == 0) 1 else 0, "\n")
+}