Week 147: Go solutions

2 files changed, 87 insertions, 0 deletions

diff --git a/challenge-147/abigail/go/ch-1.go b/challenge-147/abigail/go/ch-1.go
new file mode 100644
index 0000000000..a71d770cb3
--- /dev/null
+++ b/challenge-147/abigail/go/ch-1.go
@@ -0,0 +1,56 @@
+package main
+
+//
+// See https://theweeklychallenge.org/blog/perl-weekly-challenge-147
+//
+
+//
+// Run as: go run ch-1.go
+//
+
+import (
+    "fmt"
+)
+
+func is_prime (num int) bool {
+    if num == 2 {
+        return true
+    }
+    if num % 2 == 0 {
+        return false
+    }
+    for i := 3; i * i <= num; i += 2 {
+        if num % i == 0 {
+            return false
+        }
+    }
+    return true
+}
+
+func main () {
+    todo := [] int {2, 3, 5, 7}
+    for _, n := range todo {
+        fmt . Printf ("%d ", n)
+    }
+    count := 20 - len (todo)
+    pow   := 10
+    for count > 0 && len (todo) > 0 {
+        new_todo := [] int {}
+        for d := 1; (d <= 9) && (count > 0); d ++ {
+            for _, p := range (todo) {
+                candidate := d * pow + p
+                if is_prime (candidate) {
+                    fmt . Printf ("%d ", candidate)
+                    new_todo = append (new_todo, candidate)
+                    count --
+                }
+                if count <= 0 {
+                    break
+                }
+            }
+        }
+        todo = new_todo
+        pow *= 10
+    }
+    fmt . Print ("\n")
+}
diff --git a/challenge-147/abigail/go/ch-2.go b/challenge-147/abigail/go/ch-2.go
new file mode 100644
index 0000000000..13fe915ad4
--- /dev/null
+++ b/challenge-147/abigail/go/ch-2.go
@@ -0,0 +1,31 @@
+package main
+
+//
+// See https://theweeklychallenge.org/blog/perl-weekly-challenge-147
+//
+
+//
+// Run as: go run ch-2.go
+//
+
+import (
+    "fmt"
+)
+
+func main () {
+    p := 0
+    n := 0
+    pentagon := map [int] bool { }
+    for {
+        p = p + n + n + n + 1
+        n ++
+        pentagon [p] = true
+        for seen := range pentagon {
+            if seen + seen < p && pentagon [p - seen] &&
+                                  pentagon [p - seen - seen] {
+                fmt . Printf ("%d %d\n", seen, p - seen)
+                return
+            }
+        }
+    }
+}