Week 147: Node.js solutions

2 files changed, 76 insertions, 0 deletions

diff --git a/challenge-147/abigail/node/ch-1.js b/challenge-147/abigail/node/ch-1.js
new file mode 100644
index 0000000000..2a6c5c3764
--- /dev/null
+++ b/challenge-147/abigail/node/ch-1.js
@@ -0,0 +1,47 @@
+#!/usr/local/bin/node
+
+//
+// See https://theweeklychallenge.org/blog/perl-weekly-challenge-147
+//
+
+//
+// Run as: node ch-1.js
+//
+
+function is_prime (p) {
+    if (p == 2) {return true}
+    if (p % 2 == 0) {return false}
+    for (let i = 3; i * i <= p; i += 2) {
+        if (p % i == 0) {return false}
+    }
+    return true
+}
+
+let todo  = [2, 3, 5, 7]
+let count = 20 - todo . length
+
+todo . forEach (p => process . stdout . write (p . toString () + " "))
+
+let pow = 10
+main: {
+    while (todo . length > 0) {
+        let new_todo = []
+        for (let d = 1; d <= 9; d ++) {
+            for (let i = 0; i < todo . length; i ++) {
+                let candidate = d * pow + todo [i]
+                if (is_prime (candidate)) {
+                    new_todo . push (candidate)
+                    process . stdout . write (candidate . toString () + " ")
+                    count --
+                    if (count <= 0) {
+                        break main
+                    }
+                }
+            }
+        }
+        todo = new_todo
+        pow *= 10
+    }
+}
+
+process . stdout . write ("\n")
diff --git a/challenge-147/abigail/node/ch-2.js b/challenge-147/abigail/node/ch-2.js
new file mode 100644
index 0000000000..e06832ee9b
--- /dev/null
+++ b/challenge-147/abigail/node/ch-2.js
@@ -0,0 +1,29 @@
+#!/usr/local/bin/node
+
+//
+// See https://theweeklychallenge.org/blog/perl-weekly-challenge-147
+//
+
+//
+// Run as: node ch-2.js
+//
+
+let pentagon = {}
+let p = 0
+let n = 0
+
+main: {
+    while (1) {
+        p += n + n + n + 1
+        n ++
+        pentagon [p] = 1
+        for (let seen in pentagon) {
+            seen = +seen
+            if (seen + seen <= p && (p - seen)        in pentagon &&
+                                    (p - seen - seen) in pentagon) {
+                console . log (seen . toString () + " " + (p - seen))
+                break main
+            }
+        }
+    }
+}