Week 147: bash solutions

2 files changed, 85 insertions, 0 deletions

diff --git a/challenge-147/abigail/bash/ch-1.sh b/challenge-147/abigail/bash/ch-1.sh
new file mode 100644
index 0000000000..1f5f09be50
--- /dev/null
+++ b/challenge-147/abigail/bash/ch-1.sh
@@ -0,0 +1,55 @@
+#!/bin/sh
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-147
+#
+
+#
+# Run as: bash ch-1.sh
+#
+
+set -f
+
+function is_prime () {
+    local n=$1
+    local i
+    is_prime=1
+    if ((n > 2 && n % 2 == 0)) 
+    then is_prime=0
+    else for ((i = 3; i * i <= n && is_prime == 1; i += 2))
+         do  if ((n % i == 0))
+             then is_prime=0
+             fi
+         done
+    fi
+}
+
+todo=(2 3 5 7)
+count=20
+
+for p in "${todo[@]}"
+do  printf "$p "
+    ((count --))
+done
+
+
+while ((count > 0))
+do    next=()
+      for ((d = 1; d <= 9 && count > 0; d ++))
+      do  for p in "${todo[@]}"
+          do  candidate=$d$p
+              is_prime $candidate
+              if (($is_prime == 1))
+              then printf $candidate" "
+                   ((count --))
+                   next+=($candidate)
+                   if ((count <= 0))
+                   then break
+                   fi
+              fi
+          done
+     done
+     todo=("${next[@]}")
+done
+
+echo
diff --git a/challenge-147/abigail/bash/ch-2.sh b/challenge-147/abigail/bash/ch-2.sh
new file mode 100644
index 0000000000..f38223377d
--- /dev/null
+++ b/challenge-147/abigail/bash/ch-2.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+
+#
+# See https://theweeklychallenge.org/blog/perl-weekly-challenge-147
+#
+
+#
+# Run as: bash ch-2.sh
+#
+
+set -f
+
+declare -A pentagon
+
+# ((n = 0))
+# ((p = 0))
+
+while true
+do    ((p = p + n + n + n + 1))
+      ((n ++))
+      pentagon[$p]=1
+
+      for seen in "${!pentagon[@]}"
+      do  if ((seen + seen < p)) && [ -v pentagon[$((p - seen))] -a \
+                                      -v pentagon[$((p - seen - seen))] ]
+          then echo $seen" "$((p - seen))
+               break 2
+          fi
+      done
+done