rename repo, subdir for yearly challenges

2020/day20/ex1.bash

@@ -0,0 +1,73 @@
+#!/bin/bash
+#
+# ex1.bash: Advent2020 game, day 20/game 1.
+
+CMD=${0##*/}
+set -o noglob
+shopt -s extglob
+
+#declare -A strings
+declare -a strings T R B L RT RR RB RL nums
+
+declare -i count=-1
+while read -r line; do
+    case ${line:0:1} in
+        T*)
+            ((count++))
+            num=${line##* }
+            num=${num%%:}
+            nums+=("$num")
+            ;;
+        \#|.)
+            strings[$count]="${strings[$count]} $line"
+            ;;
+    esac
+done
+((count--))
+
+for key in "${!nums[@]}"; do
+    # shellcheck disable=SC2206
+    str=(${strings[$key]})
+    top="${str[0]}"
+    bottom="${str[9]}"
+    T+=("$top")
+    B+=("$bottom")
+    # find out right and bottom
+    unset left right
+    for ((i=0; i<10; ++i)); do
+        left+=${str[$i]:0:1}
+        right+=${str[$i]: -1:1}
+    done
+    R+=("$right")
+    L+=("$left")
+    unset fliptop flipbottom flipleft flipright
+    for ((i=9; i>=0; --i)); do
+        fliptop+=${top:$i:1}
+        flipbottom+=${bottom:$i:1}
+        flipleft+=${left:$i:1}
+        flipright+=${right:$i:1}
+    done
+    RT+=("$fliptop")
+    RR+=("$flipright")
+    RB+=("$flipbottom")
+    RL+=("$flipleft")
+
+done
+
+ALL=("${T[@]}" "${R[@]}" "${B[@]}" "${L[@]}" "${RT[@]}" "${RR[@]}" "${RB[@]}" "${RL[@]}")
+declare -i res=1 count
+for ((i=0; i<${#nums[@]}; ++i)); do
+    count=0
+
+    for t in ${T[$i]} ${R[$i]} ${B[$i]} ${L[$i]}; do
+        for s in "${ALL[@]}"; do
+            [[ $t == "$s" ]] && ((count++))
+        done
+    done
+
+    ((count ==6)) && ((res*=${nums[$i]}))
+done
+
+printf "%s : res=%d\n" "$CMD" "$res"
+
+exit 0