rename repo, subdir for yearly challenges

2020/day11/ex1.bash

@@ -0,0 +1,103 @@
+#!/bin/bash
+#
+# ex1.bash: Advent2020 game, day 11/game 1.
+
+CMD=${0##*/}
+shopt -s extglob
+
+declare -a rowsstr rows
+declare -i NCOLS NROWS
+declare zeroed
+
+function run() {
+	local -i c r cell
+	local -a seats control
+	local -i changed=1
+	local -i loop=0 seated=0
+
+	read -ra seats <<< "${rows[*]}"
+	while ((changed > 0)); do
+		changed=0
+		seated=0
+		read -ra control <<< "$zeroed"
+		for ((r=0; r<NROWS; ++r)); do
+			for ((c=0; c<NCOLS; ++c)); do
+				((cell=r*NCOLS+c))
+				if (( seats[cell] == 2 )); then
+					((control[(r)*(NCOLS+2) + c  ]++))
+					((control[(r)*(NCOLS+2) + c+1]++))
+					((control[(r)*(NCOLS+2) + c+2]++))
+
+					((control[(r+1)*(NCOLS+2) + c  ]++))
+					# this cell: control[(r+1)*(NCOLS+2) + c+1]
+					((control[(r+1)*(NCOLS+2) + c+2]++))
+
+					((control[(r+2)*(NCOLS+2) + c  ]++))
+					((control[(r+2)*(NCOLS+2) + c+1]++))
+					((control[(r+2)*(NCOLS+2) + c+2]++))
+				fi
+			done
+		done
+		for ((r=0; r<NROWS; ++r)); do
+			for ((c=0; c<NCOLS; ++c)); do
+				((cell=r*NCOLS+c))
+				((ccell=(r+1)*(NCOLS+2) + c+1))
+				case ${seats[cell]} in
+					0) continue
+					   ;;
+					1) if (( control[ccell] == 0 )); then
+						   ((++changed))
+						   seats[cell]=2
+					   fi
+					   ;;
+					2) if (( control[ccell] >= 4 )); then
+						   ((++changed))
+						   seats[cell]=1
+					   fi
+				esac
+				#printf "r=%d c=%d cell=%d val=%s\n" "$r" "$c" "$cell" "${seats[cell]}"
+			done
+			#echo
+		done
+
+		for ((r=0; r<NROWS; ++r)); do
+			for ((c=0; c<NCOLS; ++c)); do
+				((cell=(r*(NCOLS))+c))
+				((seats[cell] == 2)) && ((seated++))
+			done
+		done
+
+		((loop++))
+	done
+	echo "$seated"
+}
+
+
+
+readarray -t rowsstr
+
+for ((i=0; i<${#rowsstr[@]}; ++i)); do
+	rowsstr[i]=${rowsstr[i]//./0}
+	rowsstr[i]=${rowsstr[i]//L/1}
+	rowsstr[i]=${rowsstr[i]//#/2}
+done
+
+NCOLS=${#rowsstr[0]}
+NROWS=${#rowsstr[@]}
+
+printf -v zeroed '%0.s0 ' $(seq 1 $(((NCOLS+2)*(NROWS+2))))
+
+# split arrays in integers
+for ((r=0; r<NROWS; ++r)); do
+	srow="${rowsstr[r]}"
+	nrow=()
+	for ((c=0 ; c<NCOLS ; c++ )); do
+		nrow+=("${srow:c:1}")
+	done
+	rows[r]="${nrow[*]}"
+done
+
+res=$(run)
+printf "%s : res=%d\n" "$CMD" "$res"
+
+exit 0