Working day 17 part 1

2024/day-16/solution-1.sh

@@ -83,28 +83,33 @@ done
 CHECKPOINT_ARRAY[$END_POSITION]=0
 printf "%s " "${!CHECKPOINT_ARRAY[@]}"
 printf "\n"
+CHECKPOINT_ARRAY_LEN=${#CHECKPOINT_ARRAY[@]}
 
 # Iterate over checkpoints and print pairings
 declare -A CHECKPOINT_PAIRS
 declare -A CHECKPOINT_PAIR_WEIGHTS
+PREV_UP=$(( 2 * 5 * 7 ))
+PREV_DOWN=$(( 3 * 5 * 7 ))
+PREV_LEFT=$(( 2 * 3 * 5 ))
+PREV_RIGHT=$(( 2 * 3 * 7 ))
 get_weight_change () {
   local POSITION=$1
   local NEXT_POSITION=$2
   local DIRECTION=$3
-  # For same directions, weight change is 1
+  # Check if next position is moving in line with the previous direction
-  if [[ $(( NEXT_POSITION - POSITION )) -eq $DIR_UP ]] && [[ $(( DIRECTION % 2 )) -eq 0 ]]
+  if [[ $(( NEXT_POSITION - POSITION )) -eq $DIR_UP ]] && [[ $(( DIRECTION % PREV_UP )) -eq 0 ]]
   then
     printf "1"
     return 0
-  elif [[ $(( NEXT_POSITION - POSITION )) -eq $DIR_DOWN ]] && [[ $(( DIRECTION % 3 )) -eq 0 ]]
+elif [[ $(( NEXT_POSITION - POSITION )) -eq $DIR_DOWN ]] && [[ $(( DIRECTION % PREV_DOWN )) -eq 0 ]]
   then
     printf "1"
     return 0
-  elif [[ $(( NEXT_POSITION - POSITION )) -eq $DIR_LEFT ]] && [[ $(( DIRECTION % 5 )) -eq 0 ]]
+elif [[ $(( NEXT_POSITION - POSITION )) -eq $DIR_LEFT ]] && [[ $(( DIRECTION % PREV_LEFT )) -eq 0 ]]
   then
     printf "1"
     return 0
-  elif [[ $(( NEXT_POSITION - POSITION )) -eq $DIR_RIGHT ]] && [[ $(( DIRECTION % 7 )) -eq 0 ]]
+elif [[ $(( NEXT_POSITION - POSITION )) -eq $DIR_RIGHT ]] && [[ $(( DIRECTION % PREV_RIGHT )) -eq 0 ]]
   then
     printf "1"
     return 0
@@ -113,18 +118,22 @@ get_weight_change () {
   printf "1000"
 }
 recurse_travel () {
-  local POSITION=$1
+  local POSITION=$1 # Current position
-  local CHECKPOINT=$2
+  local CHECKPOINT=$2 # Previous checkpoint
-  local DIRECTION=$3
+  local DIRECTION=$3 # Allowed adjacent tiles
-  local WEIGHT=$4
+  local WEIGHT=$4 # Weightage so far
-  local UP=$(( POSITION - MAP_WIDTH ))
+
-  local DOWN=$(( POSITION + MAP_WIDTH ))
-  local LEFT=$(( POSITION - 1 ))
-  local RIGHT=$(( POSITION + 1 ))
   # Search adjacent tiles
   # Recurse if it's movable
   # Add a checkpoint pair and weights if checkpoint found
-  if [[ $(( DIRECTION % 2 )) -eq 0 ]] && [[ $UP -gt 0 ]]
+  # 2 : Up
+  # 3 : Down
+  # 5 : Left
+  # 7 : Right
+  if [[ $(( DIRECTION % 2 )) -eq 0 ]]
+  then
+    local UP=$(( POSITION + DIR_UP ))
+    if [[ $UP -gt 0 ]]
     then
       if [[ ${MAP_ARRAY[$UP]} == "." ]]
       then
@@ -133,11 +142,15 @@ recurse_travel () {
       elif [[ -v CHECKPOINT_ARRAY[$UP] ]]
       then
         WEIGHT_CHANGE=$( get_weight_change "$POSITION" "$UP" "$DIRECTION" )
-      CHECKPOINT_PAIRS[$UP]=$CHECKPOINT
+        CHECKPOINT_PAIRS["$CHECKPOINT-$UP"]=0
-      CHECKPOINT_PAIR_WEIGHTS["$UP-$CHECKPOINT"]=$(( WEIGHT + WEIGHT_CHANGE ))
+        CHECKPOINT_PAIR_WEIGHTS["$CHECKPOINT-$UP"]=$(( WEIGHT + WEIGHT_CHANGE ))
+      fi
     fi
   fi
   if [[ $(( DIRECTION % 3 )) -eq 0 ]] && [[ $DOWN -lt $MAP_LEN ]]
+  then
+    local DOWN=$(( POSITION + DIR_DOWN ))
+    if [[ $DOWN -lt $MAP_LEN ]]
     then 
       if [[ ${MAP_ARRAY[$DOWN]} == "." ]]
       then
@@ -146,12 +159,14 @@ recurse_travel () {
       elif [[ -v CHECKPOINT_ARRAY[$DOWN] ]]
       then
         WEIGHT_CHANGE=$( get_weight_change "$POSITION" "$DOWN" "$DIRECTION" )
-      CHECKPOINT_PAIRS[$DOWN]=$CHECKPOINT
+        CHECKPOINT_PAIRS["$CHECKPOINT-$DOWN"]=0
-      CHECKPOINT_PAIR_WEIGHTS["$DOWN-$CHECKPOINT"]=$(( WEIGHT + WEIGHT_CHANGE ))
+        CHECKPOINT_PAIR_WEIGHTS["$CHECKPOINT-$DOWN"]=$(( WEIGHT + WEIGHT_CHANGE ))
+      fi
     fi
   fi
   if [[ $(( DIRECTION % 5 )) -eq 0 ]]
   then
+    local LEFT=$(( POSITION + DIR_LEFT ))
     if [[ ${MAP_ARRAY[$LEFT]} == "." ]]
     then
       WEIGHT_CHANGE=$( get_weight_change "$POSITION" "$LEFT" "$DIRECTION" )
@@ -159,12 +174,13 @@ recurse_travel () {
     elif [[ -v CHECKPOINT_ARRAY[$LEFT] ]]
     then
       WEIGHT_CHANGE=$( get_weight_change "$POSITION" "$LEFT" "$DIRECTION" )
-      CHECKPOINT_PAIRS[$LEFT]=$CHECKPOINT
+      CHECKPOINT_PAIRS["$CHECKPOINT-$LEFT"]=0
-      CHECKPOINT_PAIR_WEIGHTS["$LEFT-$CHECKPOINT"]=$(( WEIGHT + WEIGHT_CHANGE ))
+      CHECKPOINT_PAIR_WEIGHTS["$CHECKPOINT-$LEFT"]=$(( WEIGHT + WEIGHT_CHANGE ))
     fi
   fi
   if [[ $(( DIRECTION % 7 )) -eq 0 ]]
   then
+    local RIGHT=$(( POSITION + DIR_RIGHT ))
     if [[ ${MAP_ARRAY[$RIGHT]} == "." ]]
     then
       WEIGHT_CHANGE=$( get_weight_change "$POSITION" "$RIGHT" "$DIRECTION" )
@@ -172,25 +188,66 @@ recurse_travel () {
     elif [[ -v CHECKPOINT_ARRAY[$RIGHT] ]]
     then
       WEIGHT_CHANGE=$( get_weight_change "$POSITION" "$RIGHT" "$DIRECTION" )
-      CHECKPOINT_PAIRS[$RIGHT]=$CHECKPOINT
+      CHECKPOINT_PAIRS["$CHECKPOINT-$RIGHT"]=0
-      CHECKPOINT_PAIR_WEIGHTS["$RIGHT-$CHECKPOINT"]=$(( WEIGHT + WEIGHT_CHANGE ))
+      CHECKPOINT_PAIR_WEIGHTS["$CHECKPOINT-$RIGHT"]=$(( WEIGHT + WEIGHT_CHANGE ))
     fi
   fi
 }
+ITER=99999
 for CHECKPOINT in "${!CHECKPOINT_ARRAY[@]}"
 do
-  recurse_travel "$CHECKPOINT" "$CHECKPOINT" "$CHECKPOINT" "$(( 2 * 3 * 5 * 7 ))" "0"
+  recurse_travel "$CHECKPOINT" "$CHECKPOINT" "$(( 2 * 3 * 5 * 7 ))" "0"
+  (( ITER-- ))
+  if [[ $ITER -eq 0 ]] ; then break ;fi
 done
 for CHECKPOINT in "${!CHECKPOINT_PAIRS[@]}"
 do
-  printf "DEST %s from checkpoint %s\n" "${CHECKPOINT_PAIRS[$CHECKPOINT]}" "$CHECKPOINT"
+  printf "Dest %s from checkpoint %s\n" "${CHECKPOINT_PAIRS[$CHECKPOINT]}" "$CHECKPOINT"
-done
+done | sort
 for CHECKPOINT in "${!CHECKPOINT_PAIR_WEIGHTS[@]}"
 do
   printf "Weight %s for checkpoint pair %s\n" "${CHECKPOINT_PAIR_WEIGHTS[$CHECKPOINT]}" "$CHECKPOINT"
+done | sort
+
+if [[ ${#CHECKPOINT_PAIRS[@]} -ne ${#CHECKPOINT_PAIR_WEIGHTS[@]} ]]
+then
+  printf "Checkpoint count with weight counts do not match.\n"
+fi
+
+# Map out full paths for calculate final results for it
+# Quite akin to BFS
+declare -A FINAL_PATH
+FINAL_PATH[$START_POSITION]=0
+for (( i=0 ; i<CHECKPOINT_ARRAY_LEN ; i+= 1 )) # Start to end should only have these many iterations
+do
+  for PATH in "${!FINAL_PATH[@]}"
+  do
+    CHECKPOINT=${PATH##*-}
+    PATH_SCORE=${FINAL_PATH[$PATH]}
+    if [[ $CHECKPOINT -eq $END_POSITION ]] # This path has completed
+    then
+      continue
+    fi
+    for NEXT_CHECKPOINT in "${!CHECKPOINT_ARRAY[@]}" # Check if there is a next mapping
+    do
+      if [[ $PATH =~ -$NEXT_CHECKPOINT- ]]; then continue; fi # Prevent loops
+      PAIR="$CHECKPOINT-$NEXT_CHECKPOINT"
+      if [[ -v CHECKPOINT_PAIRS[$PAIR] ]]
+      then
+	FINAL_PATH["$PATH-$NEXT_CHECKPOINT"]=$(( PATH_SCORE + ${CHECKPOINT_PAIR_WEIGHTS[$PAIR]} ))
+	unset "FINAL_PATH[$PATH]"
+      fi
+    done
+  done
 done
 
-# Score the path
+for PATH in "${!FINAL_PATH[@]}"
-#
+do
+  END=${PATH##*-}
+  if [[ $END == "$END_POSITION" ]]
+  then
+    printf "Path: %s weight: %s \n" "$PATH" "${FINAL_PATH[$PATH]}"
+  fi
+done
 
-print_map
+#print_map

2024/day-17/input

@@ -0,0 +1,5 @@
+Register A: 64196994
+Register B: 0
+Register C: 0
+
+Program: 2,4,1,1,7,5,1,5,4,0,0,3,5,5,3,0

2024/day-17/solution-1.sh

@@ -0,0 +1,145 @@
+#!/usr/bin/env bash
+
+FILE=$1
+ITER=99
+
+REG_A=$(grep 'Register A:' "$FILE" | cut -f2 -d: )
+REG_B=$(grep 'Register B:' "$FILE" | cut -f2 -d: )
+REG_C=$(grep 'Register C:' "$FILE" | cut -f2 -d: )
+read -r -a INPUT <<< "$(grep 'Program:' "$FILE" | cut -f2 -d: | tr ',' ' ' )"
+INPUT_LEN=${#INPUT[@]}
+
+printf "Registers A: %s B: %s C: %s\n" "$REG_A" "$REG_B" "$REG_C" >&2
+printf "Input : " >&2
+printf "%s " "${INPUT[@]}" >&2
+printf "\n" >&2
+
+adv () { # OPCODE 0
+  printf "OPCODE : 0 OP: adv OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  REG_A=$(( REG_A / (2 ** OPERAND) ))
+}
+bxl () { # OPCODE 1
+  printf "OPCODE : 1 OP: bxl OPERAND: %s\n" "$1" >&2
+  OPERAND=$1
+  REG_B=$(( REG_B ^ OPERAND ))
+}
+bst () { # OPCODE 2
+  printf "OPCODE : 2 OP: bst OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  REG_B=$(( OPERAND % 8 ))
+}
+jnz () { # OPCODE 3
+  printf "OPCODE : 3 OP: jnz OPERAND: %s\n" "$1" >&2
+  OPERAND=$1
+  if [[ $REG_A -eq 0 ]]
+  then
+    return 0
+  else
+    POINTER=$OPERAND
+  fi
+}
+bxc () { # OPCODE 4
+  printf "OPCODE : 4 OP: bxc OPERAND: %s\n" "$1" >&2
+  # OPERAND=$1 # Deprecated for legacy reasons
+  REG_B=$(( REG_B ^ REG_C ))
+}
+out () { # OPCODE 5
+  printf "OPCODE : 5 OP: out OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  printf "%s\n" "$(( OPERAND % 8 ))"
+}
+bdv () { # OPCODE 6
+  printf "OPCODE : 6 OP: bdv OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  REG_B=$(( REG_A / (2 ** OPERAND) ))
+}
+cdv () { # OPCODE 7
+  printf "OPCODE : 7 OP: cdv OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  REG_C=$(( REG_A / (2 ** OPERAND) ))
+}
+
+get_combo () {
+  # Interpret operand value
+  if [[ $OPERAND -eq 0 ]]
+  then
+    printf "$1"
+  elif [[ $OPERAND -eq 1 ]]
+  then
+    printf "$1"
+  elif [[ $OPERAND -eq 2 ]]
+  then
+    printf "$1"
+  elif [[ $OPERAND -eq 3 ]]
+  then
+    printf "$1"
+  elif [[ $OPERAND -eq 4 ]]
+  then
+    printf "%s" "$REG_A"
+  elif [[ $OPERAND -eq 5 ]]
+  then
+    printf "%s" "$REG_B"
+  elif [[ $OPERAND -eq 6 ]]
+  then
+    printf "%s" "$REG_C"
+  elif [[ $OPERAND -eq 7 ]]
+  then
+    printf "Reserved operand. Exiting.\n" >&2
+    exit 1
+  fi
+}
+
+check_quine () {
+  for (( i=0; i<INPUT_LEN; i++ ))
+  do
+    if [[ ${INPUT[$i]} != "${OUTPUT[$i]}" ]]
+    then
+      return 1
+    fi
+  done
+}
+
+POINTER=0
+while [[ $POINTER -lt $INPUT_LEN ]]
+do
+  OPCODE=${INPUT[$POINTER]}
+  OPERAND=${INPUT[$POINTER+1]}
+  if [[ $OPCODE -eq 0 ]]
+  then
+    adv "$OPERAND"
+    (( POINTER+=2 ))
+  elif [[ $OPCODE -eq 1 ]]
+  then
+    bxl "$OPERAND"
+    (( POINTER+=2 ))
+  elif [[ $OPCODE -eq 2 ]]
+  then
+    bst "$OPERAND"
+    (( POINTER+=2 ))
+  elif [[ $OPCODE -eq 3 ]]
+  then
+    # jnz itself moves the pointer
+    jnz "$OPERAND"
+  elif [[ $OPCODE -eq 4 ]]
+  then
+    bxc "$OPERAND"
+    (( POINTER+=2 ))
+  elif [[ $OPCODE -eq 5 ]]
+  then
+    out "$OPERAND"
+    (( POINTER+=2 ))
+  elif [[ $OPCODE -eq 6 ]]
+  then
+    bdv "$OPERAND"
+    (( POINTER+=2 ))
+  elif [[ $OPCODE -eq 7 ]]
+  then
+    cdv "$OPERAND"
+    (( POINTER+=2 ))
+  fi
+  printf "Registers A : %s B: %s C : %s\n" "$REG_A" "$REG_B" "$REG_C" >&2
+  printf "Pointer : %s\n" "$POINTER" >&2
+  (( ITER-- ))
+  if [[ $ITER -eq 0 ]] ; then break ;fi
+done | paste -s -d "," 

2024/day-17/solution-2.sh

@@ -0,0 +1,150 @@
+#!/usr/bin/env bash
+
+FILE=$1
+ITER=99
+
+REG_A=$(grep 'Register A:' "$FILE" | cut -f2 -d: )
+REG_B=$(grep 'Register B:' "$FILE" | cut -f2 -d: )
+REG_C=$(grep 'Register C:' "$FILE" | cut -f2 -d: )
+read -r -a INPUT <<< "$(grep 'Program:' "$FILE" | cut -f2 -d: | tr ',' ' ' )"
+INPUT_LEN=${#INPUT[@]}
+
+printf "Registers A: %s B: %s C: %s\n" "$REG_A" "$REG_B" "$REG_C" >&2
+printf "Input : " >&2
+printf "%s " "${INPUT[@]}" >&2
+printf "\n" >&2
+
+adv () { # OPCODE 0
+  printf "OPCODE : 0 OP: adv OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  REG_A=$(( REG_A / (2 ** OPERAND) ))
+}
+bxl () { # OPCODE 1
+  printf "OPCODE : 1 OP: bxl OPERAND: %s\n" "$1" >&2
+  OPERAND=$1
+  REG_B=$(( REG_B ^ OPERAND ))
+}
+bst () { # OPCODE 2
+  printf "OPCODE : 2 OP: bst OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  REG_B=$(( OPERAND % 8 ))
+}
+jnz () { # OPCODE 3
+  printf "OPCODE : 3 OP: jnz OPERAND: %s\n" "$1" >&2
+  OPERAND=$1
+  if [[ $REG_A -eq 0 ]]
+  then
+    return 0
+  else
+    POINTER=$OPERAND
+  fi
+}
+bxc () { # OPCODE 4
+  printf "OPCODE : 4 OP: bxc OPERAND: %s\n" "$1" >&2
+  # OPERAND=$1 # Deprecated for legacy reasons
+  REG_B=$(( REG_B ^ REG_C ))
+}
+out () { # OPCODE 5
+  printf "OPCODE : 5 OP: out OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  printf "%s\n" "$(( OPERAND % 8 ))"
+}
+bdv () { # OPCODE 6
+  printf "OPCODE : 6 OP: bdv OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  REG_B=$(( REG_A / (2 ** OPERAND) ))
+}
+cdv () { # OPCODE 7
+  printf "OPCODE : 7 OP: cdv OPERAND: %s\n" "$1" >&2
+  OPERAND=$( get_combo "$1" )
+  REG_C=$(( REG_A / (2 ** OPERAND) ))
+}
+
+get_combo () {
+  # Interpret operand value
+  if [[ $OPERAND -eq 0 ]]
+  then
+    printf "$1"
+  elif [[ $OPERAND -eq 1 ]]
+  then
+    printf "$1"
+  elif [[ $OPERAND -eq 2 ]]
+  then
+    printf "$1"
+  elif [[ $OPERAND -eq 3 ]]
+  then
+    printf "$1"
+  elif [[ $OPERAND -eq 4 ]]
+  then
+    printf "%s" "$REG_A"
+  elif [[ $OPERAND -eq 5 ]]
+  then
+    printf "%s" "$REG_B"
+  elif [[ $OPERAND -eq 6 ]]
+  then
+    printf "%s" "$REG_C"
+  elif [[ $OPERAND -eq 7 ]]
+  then
+    printf "Reserved operand. Exiting.\n" >&2
+    exit 1
+  fi
+}
+
+check_quine () {
+  for (( i=0; i<INPUT_LEN; i++ ))
+  do
+    if [[ ${INPUT[$i]} != "${OUTPUT[$i]}" ]]
+    then
+      return 1
+    fi
+  done
+}
+
+while ! check_quine
+do
+  read -r -a OUTPUT <<<"$(
+    POINTER=0
+    while [[ $POINTER -lt $INPUT_LEN ]]
+    do
+      OPCODE=${INPUT[$POINTER]}
+      OPERAND=${INPUT[$POINTER+1]}
+      if [[ $OPCODE -eq 0 ]]
+      then
+        adv "$OPERAND"
+        (( POINTER+=2 ))
+      elif [[ $OPCODE -eq 1 ]]
+      then
+        bxl "$OPERAND"
+        (( POINTER+=2 ))
+      elif [[ $OPCODE -eq 2 ]]
+      then
+        bst "$OPERAND"
+        (( POINTER+=2 ))
+      elif [[ $OPCODE -eq 3 ]]
+      then
+        # jnz itself moves the pointer
+        jnz "$OPERAND"
+      elif [[ $OPCODE -eq 4 ]]
+      then
+        bxc "$OPERAND"
+        (( POINTER+=2 ))
+      elif [[ $OPCODE -eq 5 ]]
+      then
+        out "$OPERAND"
+        (( POINTER+=2 ))
+      elif [[ $OPCODE -eq 6 ]]
+      then
+        bdv "$OPERAND"
+        (( POINTER+=2 ))
+      elif [[ $OPCODE -eq 7 ]]
+      then
+        cdv "$OPERAND"
+        (( POINTER+=2 ))
+      fi
+      printf "Registers A : %s B: %s C : %s\n" "$REG_A" "$REG_B" "$REG_C" >&2
+      printf "Pointer : %s\n" "$POINTER" >&2
+      (( ITER-- ))
+      if [[ $ITER -eq 0 ]] ; then break ;fi
+    done | paste -s -d "," 
+  )"
+done

2024/day-17/test-input-1

@@ -0,0 +1,5 @@
+Register A: 729
+Register B: 0
+Register C: 0
+
+Program: 0,1,5,4,3,0