Day 9

09/01.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+
+i_max=-1
+j_max=0
+locations=()
+marked_locations=()
+while read line; do
+  if [ $i_max -lt 0 ]; then
+    i_max=${#line}
+  fi
+  locations+=( $(sed 's/\([0-9]\)/\1 /g' <<< $line) )
+  j_max=$((j_max+1))
+done
+for i in $(seq 0 $((i_max-1))); do
+  for j in $(seq 0 $((j_max-1))); do
+    marked_locations+=( 0 )
+  done
+done
+
+for i in $(seq 0 $((i_max-1))); do
+  for j in $(seq 0 $((j_max-1))); do
+    curr_location=${locations[$((i+j*i_max))]}
+    if { [ $i -gt 0 ] && [ $curr_location -ge ${locations[$((i-1+j*i_max))]} ] ;} \
+	    || { [ $i -lt $((i_max-1)) ] && [ $curr_location -ge ${locations[$((i+1+j*i_max))]} ] ;} \
+	    || { [ $j -gt 0 ] && [ $curr_location -ge ${locations[$((i+(j-1)*i_max))]} ] ;} \
+	    || { [ $j -lt $((j_max-1)) ] && [ $curr_location -ge ${locations[$((i+(j+1)*i_max))]} ] ;}; then
+      marked_locations[$((i+j*i_max))]=1
+    fi
+  done
+done
+
+sum=0
+for i in $(seq 0 $((i_max-1))); do
+  for j in $(seq 0 $((j_max-1))); do
+    curr_location=${marked_locations[$((i+j*i_max))]}
+    if [ $curr_location -eq 0 ]; then
+      sum=$((sum+1+locations[i+j*i_max]))
+    fi
+  done
+done
+echo $sum