Node.js solution for week 3, part 2

2 files changed, 44 insertions, 0 deletions

diff --git a/challenge-003/abigail/README.md b/challenge-003/abigail/README.md
index 3f55d0e383..f0b9e8222f 100644
--- a/challenge-003/abigail/README.md
+++ b/challenge-003/abigail/README.md
@@ -41,4 +41,5 @@ rows from the command line. The Pascal Triangle should have at least
 * [AWK](awk/ch-2.awk)
 * [C](c/ch-2.c)
 * [Lua](lua/ch-2.lua)
+* [Node.js](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
diff --git a/challenge-003/abigail/node/ch-2.js b/challenge-003/abigail/node/ch-2.js
new file mode 100644
index 0000000000..ab629fcb86
--- /dev/null
+++ b/challenge-003/abigail/node/ch-2.js
@@ -0,0 +1,43 @@
+#!/usr/local/bin/node
+
+//
+// See ../README.md
+//
+
+//
+// Run as: node ch-1.js < input-file
+//
+
+require ('readline')
+. createInterface ({input: process . stdin})   
+. on ('line', _ => triangle (+_))
+;
+
+
+function triangle (rows) {
+    //
+    // Create and print the 0th row
+    //
+    let row = [1]
+    process . stdout . write ("1\n")
+    for (let r = 1; r <= rows; r ++) {
+        //
+        // Calculate a new row
+        //
+        let new_row = []
+        for (i = 0; i <= r; i ++) {
+            new_row [i] = (i == 0 ? 0 : row [i - 1]) +
+                          (i == r ? 0 : row [i]);
+            if (i > 0) {
+                process . stdout . write (" ")
+            }
+            process . stdout . write ("" + new_row [i])
+        }
+        process . stdout . write ("\n")
+
+        //
+        // New row becomes current row
+        //
+        row = new_row
+    }
+}