day 9 part 1 solution

2024/day-8/solution-2.sh

@@ -40,6 +40,7 @@ do
       while true
       do
         HEAD=$(( A - DIFF * HEADC ))
+	if [[ ${SHADOW_ARRAY[HEAD]} == "X" ]]; then (( HEADC++ )); continue ; fi
 	HEADVDIFF=$(( (A / LEN) - (HEAD / LEN) ))
         # Check if out of bounds
         if [[ $HEAD -lt ${#MAP_ARRAY[@]} ]] && \
@@ -57,6 +58,7 @@ do
       while true
       do
         TAIL=$(( B + DIFF * TAILC ))
+	if [[ ${SHADOW_ARRAY[TAIL]} == "X" ]]; then (( TAILC++ )); continue ; fi
 	TAILVDIFF=$(( (TAIL / LEN) - (B / LEN) ))
         # Check if out of bounds
         if [[ $TAIL -lt ${#MAP_ARRAY[@]} ]] && \
@@ -75,6 +77,6 @@ do
   unset IDX_ARRAY
 
 done
-printf "%s" "${SHADOW_ARRAY[@]}" | fold -w "$LEN" | sed -E 's/(.)/\1\ /g'
-printf "\n"
+#printf "%s" "${SHADOW_ARRAY[@]}" | fold -w "$LEN" | sed -E 's/(.)/\1\ /g'
+#printf "\n"
 printf "%s" "${SHADOW_ARRAY[@]}" | grep -o 'X' | wc -l

2024/day-9/solution-1.sh

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+
+FILE=input
+# Sparse sequence
+read -r -a SPARSE_ARRAY <<< "$(
+  INDEX=0
+  FILE_ID=0
+  while read -r CHAR
+  do
+    if [[ $(( INDEX % 2 )) -eq 0 ]]
+    then
+      for (( i=1; i<=$CHAR; i++ )) do printf "%s " "$FILE_ID"
+      done
+      (( FILE_ID++ ))
+    else
+      for (( i=1; i<=$CHAR; i++ ))
+      do
+        printf ". "
+      done
+    fi
+    (( INDEX++ ))
+  done <<< "$( sed -E 's/(.)/\1\n/g' "$FILE" | grep -v '^$' )"
+)"
+#printf "%s" "${SPARSE_ARRAY[@]}"
+#printf "\n"
+printf "Sparse array len: %s\n" "${#SPARSE_ARRAY[@]}"
+
+# Reverse feed
+read -r -a FEED_ARRAY <<< "$( 
+  for (( i=0; i<${#SPARSE_ARRAY[@]}; i++ ))
+  do
+    if [[ ${SPARSE_ARRAY[i]} != "." ]]
+    then
+      printf "%s " "${SPARSE_ARRAY[i]}"
+    fi
+  done
+)"
+#printf "%s" "${FEED_ARRAY[@]}"
+#printf "\n"
+printf "Reverse feed len : %s\n" "${#FEED_ARRAY[@]}"
+
+# Generate checksum for sparse array
+CHECKSUM=0
+i=0
+j=$(( ${#FEED_ARRAY[@]} - 1 ))
+for (( k=0; k<${#SPARSE_ARRAY[@]}; k++ ))
+do
+  if [[ $i -gt $j ]]; then break ; fi
+  if [[ ${SPARSE_ARRAY[k]} == '.' ]] 
+  then
+    (( CHECKSUM += k * FEED_ARRAY[j] ))
+    (( j-- ))
+  else
+    (( CHECKSUM += k * FEED_ARRAY[i] ))
+    (( i++ ))
+  fi
+done
+printf "%s" "$CHECKSUM"

2024/day-9/test-input

@@ -0,0 +1 @@
+2333133121414131402