Day 14 Working part 1

2024/day-14/solution-1.sh

@@ -0,0 +1,113 @@
+#!/usr/bin/env/bash
+
+FILE=input
+MAP_WIDTH=101
+MAP_HEIGHT=103
+MEDIAN_WIDTH=$(( MAP_WIDTH / 2 - 1 ))
+if [[ $(( MAP_WIDTH % 2 )) -eq 1 ]]
+then
+  (( MEDIAN_WIDTH++ ))
+fi
+MEDIAN_HEIGHT=$(( MAP_HEIGHT / 2 - 1 ))
+if [[ $(( MAP_HEIGHT % 2 )) -eq 1 ]]
+then
+  (( MEDIAN_HEIGHT++ ))
+fi
+printf "Median width: %s, median height: %s\n" "$MEDIAN_WIDTH" "$MEDIAN_HEIGHT"
+
+# Load bot positions and velocities
+read -r -a BOT_ARRAY <<< "$( grep -Eo '[-0-9]*' "$FILE" | paste -s -d " " )"
+#printf "%s " "${BOT_ARRAY[@]}"
+#printf "\n"
+printf "Bot array size: %s\n" "${#BOT_ARRAY[@]}"
+
+# Just move forward n seconds for every bot and save 
+# final positions
+IFS=';'; read -r -a FINAL_ARRAY <<< "$(
+  SECONDS=100
+  for (( i=0; i<${#BOT_ARRAY[@]}; i+=4 )) 
+  do
+    PX=${BOT_ARRAY[i]}
+    PY=${BOT_ARRAY[i+1]}
+    VX=${BOT_ARRAY[i+2]}
+    VY=${BOT_ARRAY[i+3]}
+    FINAL_X=$(( PX + ( VX * SECONDS ) ))
+    FINAL_Y=$(( PY + ( VY * SECONDS ) ))
+    printf "%s %s;" "$FINAL_X" "$FINAL_Y"
+  done <<< "${BOT_ARRAY[@]}"
+)"
+unset IFS
+#printf "%s\n" "${FINAL_ARRAY[@]}" | head
+printf "Final array size: %s\n" "${#FINAL_ARRAY[@]}"
+
+# Get number of robots in each quadrant
+Q1=0
+Q2=0
+Q3=0
+Q4=0
+ITER=9999
+while read -r RAW_X RAW_Y
+do
+
+  # Adjust positions to be on map
+  PX=$(( RAW_X % MAP_WIDTH ))
+  if [[ $PX -lt 0 ]]
+  then
+    PX=$(( MAP_WIDTH + PX ))
+  fi
+  PY=$(( RAW_Y % MAP_HEIGHT ))
+  if [[ $PY -lt 0 ]]
+  then
+    PY=$(( MAP_HEIGHT + PY ))
+  fi
+
+  # Check if negative positions, should not happen
+  if [[ $PX -lt 0 ]] || [[ $PY -lt 0 ]]
+  then
+    printf "Negative final position. PX: %s PY: %s\n" "$PX" "$PY"
+  fi
+  if [[ $PX -ge $MAP_WIDTH ]] || [[ $PY -ge $MAP_HEIGHT ]]
+  then
+    printf "Out of bounds. PX: %s PY: %s\n" "$PX" "$PY"
+  fi
+  printf "PX: %s PY: %s\n" "$PX" "$PY"
+
+  # Allocate robot to quadrant
+  if \
+    [[ $PX -ge 0 ]] && \
+    [[ $PX -lt $MEDIAN_WIDTH ]] && \
+    [[ $PY -ge 0 ]] && \
+    [[ $PY -lt $MEDIAN_HEIGHT ]] # Q1
+  then
+    (( Q1++ ))
+  elif \
+    [[ $PX -gt $MEDIAN_WIDTH ]] && \
+    [[ $PX -lt $MAP_WIDTH ]] && \
+    [[ $PY -ge 0 ]] && \
+    [[ $PY -lt $MEDIAN_HEIGHT ]] # Q2
+  then
+    (( Q2++ ))
+  elif \
+    [[ $PX -ge 0 ]] && \
+    [[ $PX -lt $MEDIAN_WIDTH ]] && \
+    [[ $PY -gt $MEDIAN_HEIGHT ]] && \
+    [[ $PY -lt $MAP_HEIGHT ]] # Q3
+  then
+    (( Q3++ ))
+  elif \
+    [[ $PX -gt $MEDIAN_WIDTH ]] && \
+    [[ $PX -lt $MAP_WIDTH ]] && \
+    [[ $PY -gt $MEDIAN_HEIGHT ]] && \
+    [[ $PY -lt $MAP_HEIGHT ]] # Q4
+  then
+    (( Q4++ ))
+  else
+    printf "Skipped in the median. PX: %s PY: %s\n" "$PX" "$PY"
+  fi
+  (( ITER-- ))
+  if [[ $ITER -eq 0 ]] ; then break ; fi
+done <<< "$( printf "%s\n" "${FINAL_ARRAY[@]}" )"
+
+# Calculate safety factor
+SAFETY_FACTOR=$(( Q1 * Q2 * Q3 * Q4 ))
+printf "Safety factor: %s\n" "$SAFETY_FACTOR"