Day 3

2024/day-3/solution-2.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+
+# Filter out do(), don't(), and mul()
+# then strip out tails to get do and don
+# strip out mul() to get numbers
+grep -Po 'do\(\)|don(.)?t\(\)|mul\([0-9]+,[0-9]+\)' input |
+  grep -Po 'don|do|mul\([0-9]+,[0-9]+\)' |
+  sed -E 's/^mul\(([0-9]+),([0-9]+)\)/\1 \2/g' |
+  awk '
+    BEGIN {
+      total = 0
+      todo = 1
+    }
+    {
+      if ($1 == "don") {
+        todo = 0
+      } else if ($1 == "do") {
+        todo = 1
+      } else if (todo == 1){
+        total += $1 * $2 
+      }
+    }
+    END {
+      print total
+    }'