From 467f8f499a0d2aabf12e09ac876e981a775ffa70 Mon Sep 17 00:00:00 2001
From: Pierre Jeanjean <rhiobet@gmail.com>
Date: Mon, 20 Dec 2021 20:38:33 +0100
Subject: [PATCH] Day 20

---
 20/01.sh | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 20/02.sh | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 214 insertions(+)
 create mode 100755 20/01.sh
 create mode 100755 20/02.sh

diff --git a/20/01.sh b/20/01.sh
new file mode 100755
index 0000000..a4aa517
--- /dev/null
+++ b/20/01.sh
@@ -0,0 +1,107 @@
+#!/bin/bash
+
+read line
+enhancement=( $(sed -e 's/\./ 0 /g' -e 's/\#/ 1 /g' <<< $line) )
+
+read line
+
+declare -A image
+invisible_pixels_color=0
+i=0
+i_max=0
+i_min=0
+j_min=0
+while read line; do
+  j_max=${#line}
+  for ((j=0;j<j_max;j++)); do
+    if [[ ${line:$j:1} == '.' ]]; then
+      image[$i,$j]=0
+    else
+      image[$i,$j]=1
+    fi
+  done
+  i=$((i+1))
+done
+i_max=$i
+
+for ((nb_iter=0;nb_iter<2;nb_iter++)); do
+  declare -A new_image
+  i_min=$((i_min-1))
+  j_min=$((j_min-1))
+  i_max=$((i_max+1))
+  j_max=$((j_max+1))
+  for ((i=i_min;i<i_max;i++)); do
+    for ((j=j_min;j<j_max;j++)); do
+      if [ -z ${image[$i,$j]} ]; then
+        image[$i,$j]=$invisible_pixels_color
+      fi
+    done
+  done
+  for ((i=i_min;i<i_max;i++)); do
+    for ((j=j_min;j<j_max;j++)); do
+      new_color=''
+      if [ $i -gt $i_min ]; then
+        if [ $j -gt $j_min ]; then
+          new_color=$new_color${image[$((i-1)),$((j-1))]}
+        else
+          new_color=$new_color$invisible_pixels_color
+        fi
+        new_color=$new_color${image[$((i-1)),$j]}
+        if [ $j -lt $((j_max-1)) ]; then
+          new_color=$new_color${image[$((i-1)),$((j+1))]}
+        else
+          new_color=$new_color$invisible_pixels_color
+        fi
+      else
+        new_color=$new_color$invisible_pixels_color$invisible_pixels_color$invisible_pixels_color
+      fi
+      if [ $j -gt $j_min ]; then
+        new_color=$new_color${image[$i,$((j-1))]}
+      else
+        new_color=$new_color$invisible_pixels_color
+      fi
+      new_color=$new_color${image[$i,$j]}
+      if [ $j -lt $((j_max-1)) ]; then
+        new_color=$new_color${image[$i,$((j+1))]}
+      else
+        new_color=$new_color$invisible_pixels_color
+      fi
+      if [ $i -lt $((i_max-1)) ]; then
+        if [ $j -gt $j_min ]; then
+          new_color=$new_color${image[$((i+1)),$((j-1))]}
+        else
+          new_color=$new_color$invisible_pixels_color
+        fi
+        new_color=$new_color${image[$((i+1)),$j]}
+        if [ $j -lt $((j_max-1)) ]; then
+          new_color=$new_color${image[$((i+1)),$((j+1))]}
+        else
+          new_color=$new_color$invisible_pixels_color
+        fi
+      else
+        new_color=$new_color$invisible_pixels_color$invisible_pixels_color$invisible_pixels_color
+      fi
+      new_image[$i,$j]=${enhancement[$((2#${new_color}))]}
+    done
+  done
+  for ((i=i_min;i<i_max;i++)); do
+    for ((j=j_min;j<j_max;j++)); do
+      image[$i,$j]=${new_image[$i,$j]}
+    done
+  done
+  if [ $invisible_pixels_color -eq 0 ]; then
+    invisible_pixels_color=${enhancement[0]}
+  else
+    invisible_pixels_color=${enhancement[511]}
+  fi
+done
+
+n_pixels_lit=0
+for ((i=i_min;i<i_max;i++)); do
+  for ((j=j_min;j<j_max;j++)); do
+    if [ ${image[$i,$j]} -eq 1 ]; then
+      n_pixels_lit=$((n_pixels_lit+1))
+    fi
+  done
+done
+echo $n_pixels_lit
diff --git a/20/02.sh b/20/02.sh
new file mode 100755
index 0000000..6c09c78
--- /dev/null
+++ b/20/02.sh
@@ -0,0 +1,107 @@
+#!/bin/bash
+
+read line
+enhancement=( $(sed -e 's/\./ 0 /g' -e 's/\#/ 1 /g' <<< $line) )
+
+read line
+
+declare -A image
+invisible_pixels_color=0
+i=0
+i_max=0
+i_min=0
+j_min=0
+while read line; do
+  j_max=${#line}
+  for ((j=0;j<j_max;j++)); do
+    if [[ ${line:$j:1} == '.' ]]; then
+      image[$i,$j]=0
+    else
+      image[$i,$j]=1
+    fi
+  done
+  i=$((i+1))
+done
+i_max=$i
+
+for ((nb_iter=0;nb_iter<50;nb_iter++)); do
+  declare -A new_image
+  i_min=$((i_min-1))
+  j_min=$((j_min-1))
+  i_max=$((i_max+1))
+  j_max=$((j_max+1))
+  for ((i=i_min;i<i_max;i++)); do
+    for ((j=j_min;j<j_max;j++)); do
+      if [ -z ${image[$i,$j]} ]; then
+        image[$i,$j]=$invisible_pixels_color
+      fi
+    done
+  done
+  for ((i=i_min;i<i_max;i++)); do
+    for ((j=j_min;j<j_max;j++)); do
+      new_color=''
+      if [ $i -gt $i_min ]; then
+        if [ $j -gt $j_min ]; then
+          new_color=$new_color${image[$((i-1)),$((j-1))]}
+        else
+          new_color=$new_color$invisible_pixels_color
+        fi
+        new_color=$new_color${image[$((i-1)),$j]}
+        if [ $j -lt $((j_max-1)) ]; then
+          new_color=$new_color${image[$((i-1)),$((j+1))]}
+        else
+          new_color=$new_color$invisible_pixels_color
+        fi
+      else
+        new_color=$new_color$invisible_pixels_color$invisible_pixels_color$invisible_pixels_color
+      fi
+      if [ $j -gt $j_min ]; then
+        new_color=$new_color${image[$i,$((j-1))]}
+      else
+        new_color=$new_color$invisible_pixels_color
+      fi
+      new_color=$new_color${image[$i,$j]}
+      if [ $j -lt $((j_max-1)) ]; then
+        new_color=$new_color${image[$i,$((j+1))]}
+      else
+        new_color=$new_color$invisible_pixels_color
+      fi
+      if [ $i -lt $((i_max-1)) ]; then
+        if [ $j -gt $j_min ]; then
+          new_color=$new_color${image[$((i+1)),$((j-1))]}
+        else
+          new_color=$new_color$invisible_pixels_color
+        fi
+        new_color=$new_color${image[$((i+1)),$j]}
+        if [ $j -lt $((j_max-1)) ]; then
+          new_color=$new_color${image[$((i+1)),$((j+1))]}
+        else
+          new_color=$new_color$invisible_pixels_color
+        fi
+      else
+        new_color=$new_color$invisible_pixels_color$invisible_pixels_color$invisible_pixels_color
+      fi
+      new_image[$i,$j]=${enhancement[$((2#${new_color}))]}
+    done
+  done
+  for ((i=i_min;i<i_max;i++)); do
+    for ((j=j_min;j<j_max;j++)); do
+      image[$i,$j]=${new_image[$i,$j]}
+    done
+  done
+  if [ $invisible_pixels_color -eq 0 ]; then
+    invisible_pixels_color=${enhancement[0]}
+  else
+    invisible_pixels_color=${enhancement[511]}
+  fi
+done
+
+n_pixels_lit=0
+for ((i=i_min;i<i_max;i++)); do
+  for ((j=j_min;j<j_max;j++)); do
+    if [ ${image[$i,$j]} -eq 1 ]; then
+      n_pixels_lit=$((n_pixels_lit+1))
+    fi
+  done
+done
+echo $n_pixels_lit