Initial Commit - days 01-12

day12/ex1.bash

@@ -0,0 +1,53 @@
+#!/bin/bash
+#
+# ex1.bash: Advent2020 game, day 12/game 1.
+
+CMD=${0##*/}
+shopt -s extglob
+
+declare -i X=0 Y=0
+declare -i DIRECTION=90 REAL
+
+while read -r line; do
+	C=${line:0:1}
+	A=${line:1}
+	#printf "CMD=%s ARG=%d\n" "$C" "$A"
+
+	case "$C" in
+		R) ((DIRECTION=(DIRECTION+A)%360))
+		   #printf "D=%d\n" "$DIRECTION"
+		   ;;
+		L) ((DIRECTION=(DIRECTION+360-A)%360))
+		   #printf "D=%d\n" "$DIRECTION"
+		   ;;
+		F) REAL=$DIRECTION
+		   ;;
+		N) REAL=0
+		   ;;
+		S) REAL=180
+		   ;;
+		E) REAL=90
+		   ;;
+		W) REAL=270
+		   ;;
+	esac
+	if [[ "$C" != "R" && "$C" != "L" ]]; then
+		case "$REAL" in
+			0) ((Y+=A))
+			   ;;
+			90) ((X+=A))
+				;;
+			180) ((Y-=A))
+				 ;;
+			270) ((X-=A))
+				 ;;
+		esac
+	fi
+	#printf "D=%3d POS=(%d,%d)\n" "$DIRECTION" "$X" "$Y"
+done
+
+((X<0)) && ((X=-X))
+((Y<0)) && ((Y=-Y))
+printf "%s : res=%d\n" "$CMD" $((X+Y))
+
+exit 0