From a9e4013969ba39c66be5dbafdbbbde9194dd3fe6 Mon Sep 17 00:00:00 2001
From: Clement <clementchiew95@disroot.org>
Date: Fri, 6 Dec 2024 01:09:33 +0800
Subject: [PATCH] Use awk match instead of grep loop

---
 2024/day-5/solution-2.sh | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/2024/day-5/solution-2.sh b/2024/day-5/solution-2.sh
index be100e7..2cbc576 100644
--- a/2024/day-5/solution-2.sh
+++ b/2024/day-5/solution-2.sh
@@ -1,25 +1,21 @@
 #!/usr/bin/env bash
 
+INPUT_RULES=$(cat input-rules)
 {
   while read -r LINE
   do
     GREP_EXPR=$( printf "%s"  "$LINE" | tr ',' '|' )
-    MATCH_COUNT=0
-    # Loop through rules and find a breaking rule
-    while read -r RULE
-    do
-      GREPC=$( printf "%s" "$LINE" | grep -c "$RULE" ) 
-      if [[ $GREPC -ne 1 ]]
-      then
-        #printf "%s rule violated for %s \n" "$RULE" "$LINE"
-        MATCH_COUNT=1
-        break
-      fi
-    # Filter rules that only has included pages
-    done <<< "$( < input-rules grep -E "($GREP_EXPR)\\|($GREP_EXPR)" | sed 's/|/,.*/')" 
-  
+    BEEG_AWK_EXPR=$( 
+      printf "%s" "$INPUT_RULES" | 
+      grep -E "($GREP_EXPR)\\|($GREP_EXPR)" | 
+      sed -E 's/(.*)\|(.*)/\1,.*\2/; s&^&/&; s&$&/&' | 
+      paste -s -d '@' | 
+      sed 's/@/ \&\& /g' 
+    )
+    AWK_MATCH=$( printf "%s" "$LINE" | awk "$BEEG_AWK_EXPR" | wc -c )
+
     # Don't process for valid lines
-    [[ $MATCH_COUNT -eq 0 ]] && continue
+    if [[ $AWK_MATCH -gt 0 ]] ; then continue; fi
     printf "%s\n" "$LINE"
   
   done < input-updates