Implemented caching system

2024/day-11/solution-2.sh

@@ -1,7 +1,13 @@
 #!/usr/bin/env bash
 
+declare -A KV_CACHE
 read -r -a ROCK_LIST <<< "$( cat input )"
-BLINK_NUM=25
+DUMP_KV_CACHE=0
+BLINK_NUM=75
+# KV Cache provides n depth search, 
+# but must always be fully divisible by BLINK_NUM
+DEPTH=5 
+if [[ $(( BLINK_NUM % DEPTH )) -gt 0 ]] ;then printf "BLINK_NUM DEPTH mismatch.\n" && exit ; fi
 
 ROCK_RETURN=()
 ROCK_NUM=0
@@ -10,7 +16,7 @@ blink_rock () {
   #printf "Blinking rock : %s\n" "$ROCK_NUM" >&2
 
   # Remove leading zeroes
-  ROCK_NUM=$(( 10#$ROCK_NUM ))
+  #ROCK_NUM=$(( 10#$ROCK_NUM ))
   # Rule 1 : Convert 0 to 1
   if [[ $ROCK_NUM -eq 0 ]]
   then
@@ -23,7 +29,7 @@ blink_rock () {
   if [[ $(( DIGIT_COUNT % 2 )) -eq 0 ]] && [[ $DIGIT_COUNT -gt 0 ]]
   then
     HALF=$(( DIGIT_COUNT / 2 ))
-    read -r -a ROCK_RETURN <<< "$( printf "%s %s " "${ROCK_NUM:0:$HALF}" "${ROCK_NUM:$HALF}" )"
+    read -r -a ROCK_RETURN <<< "$( printf "%s %s " "$(( 10#${ROCK_NUM:0:$HALF} ))" "$(( 10#${ROCK_NUM:$HALF} ))" )"
     return    
   fi
 
@@ -49,18 +55,56 @@ blink_rocks () {
   #printf "\n" >&2
 }
 
-FINAL_LIST=()
-for ROCK_NUM in "${ROCK_LIST[@]}"
+#FINAL_LIST=()
+# Keeps track of 
+read -r -a FINAL_LIST <<< "$( printf "%s " "${ROCK_LIST[@]}" )"
+POSITION=0
+while [[ $POSITION -lt $BLINK_NUM ]]
 do
-  printf "Rock: %s\n" "$ROCK_NUM"
-  ROCKS_TO_BLINK=( "$ROCK_NUM" )
-  for (( i=0 ; i< BLINK_NUM; i++ ))
+  printf "%s Working on position %s\n" "$( date )" "$POSITION"
+  INTER_LIST_1=()
+  # Essentially move $DEPTH steps at a time
+  for ROCK in "${FINAL_LIST[@]}"
   do
-    blink_rocks
-    ROCKS_TO_BLINK=( "${BLINKED_ROCKS[@]}" )
+    # Check if this is already cached
+    if [[ -v KV_CACHE["$ROCK"] ]]
+    then
+      # Retrieve cached entry
+      read -r -a X <<< "${KV_CACHE[$ROCK]}"
+      INTER_LIST_1+=( "${X[@]}" )
+      #printf "Cache hit. Key: %s, Value: " "$ROCK"
+      #printf "%s " "${KV_CACHE[$ROCK]}"
+      #printf "\n"
+    else
+      # Build cache entry
+      ROCKS_TO_BLINK=( "$ROCK" )
+      for (( i=0; i<DEPTH; i++ ))
+      do
+        blink_rocks
+        read -r -a ROCKS_TO_BLINK <<< "$( printf "%s " "${BLINKED_ROCKS[@]}" )"
+      done
+      KV_CACHE[$ROCK]=$( printf "%s " "${BLINKED_ROCKS[@]}" )
+      INTER_LIST_1+=( "${BLINKED_ROCKS[@]}" )
+    fi
   done
-  FINAL_LIST+=( "${BLINKED_ROCKS[@]}" )
+
+  read -r -a FINAL_LIST <<< "$( printf "%s " "${INTER_LIST_1[@]}" )"
+
+  # All rocks are calculated $DEPTH ahead
+  (( POSITION+=DEPTH ))
 done
-printf "%s " "${FINAL_LIST[@]}"
-printf "\n"
+#FINAL_LIST+=( "${BLINKED_ROCKS[@]}" )
+
+# Dump KV cache for debugging
+if [[ $DUMP_KV_CACHE -eq 0 ]]
+then
+  printf "Number of keys in KV cache: %s\n" "${#KV_CACHE[@]}"
+  printf "Dumping KV CACHE\n"
+  for KEY in "${!KV_CACHE[@]}"
+  do
+    printf "Key: %s, Value: %s\n" "$KEY" "${KV_CACHE[$KEY]}"
+  done | sort
+fi
+#printf "%s " "${FINAL_LIST[@]}"
+#printf "\n"
 printf "%s\n" "${#FINAL_LIST[@]}"