From 12d4bdda616493c0aa240eb4a7d33269d4ee0448 Mon Sep 17 00:00:00 2001
From: Bruno Raoult <braoult@gmail.com>
Date: Sun, 1 Aug 2021 17:33:20 +0200
Subject: [PATCH] 1st version of Bash for Day22/Part 2 (works on TEST.txt)

---
 2020/day22/TEST1.txt |   8 ++++
 2020/day22/ex2.bash  | 110 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 118 insertions(+)
 create mode 100644 2020/day22/TEST1.txt
 create mode 100755 2020/day22/ex2.bash

diff --git a/2020/day22/TEST1.txt b/2020/day22/TEST1.txt
new file mode 100644
index 0000000..a29e13a
--- /dev/null
+++ b/2020/day22/TEST1.txt
@@ -0,0 +1,8 @@
+Player 1:
+43
+19
+
+Player 2:
+2
+29
+14
diff --git a/2020/day22/ex2.bash b/2020/day22/ex2.bash
new file mode 100755
index 0000000..d9bc07f
--- /dev/null
+++ b/2020/day22/ex2.bash
@@ -0,0 +1,110 @@
+#!/bin/bash
+#
+# ex1.bash: Advent2020 game, day 22/game 1.
+
+CMD=${0##*/}
+shopt -s extglob
+set -o noglob
+
+declare -a cards=() CARDS1=() CARDS2=()
+declare -i count=-1
+
+while read -r line; do
+    case ${line:0:1} in
+        P*)
+            ((count++))
+            ;;
+        [1-9]*)
+            cards[$count]+=" $line"
+            ;;
+    esac
+done
+# shellcheck disable=SC2206
+CARDS1=(${cards[0]}) && CARDS2=(${cards[1]})
+
+
+# params: (%d)depth (int ref)result (array name)player1 (array name)player2
+
+declare -i game=0
+run() {
+    local -n _res="$1" _p1="$2" _p2="$3"
+    local -a p1=(${_p1[@]}) p2=(${_p2[@]}) sp1 sp2
+    local -A hash=()
+    local winner=0 round=1 g                    # 1: p1, 2: p2
+    local str
+    ((game++))
+    g=$game
+    printf "\n=== Game %d ===\n" "$g"
+    #printf "   p1=%s \n" "${p1[*]}"
+    #printf "   p2=%s \n" "${p2[*]}"
+    while ((${#p1[@]} && ${#p2[@]})); do
+        echo
+        echo -n "-- "
+        printf "Round %d (Game %d) --\n" "$round" "$g"
+        S="${p1[*]}"
+        S="${S// /, }"
+        printf "Player 1's deck: %s\n" "$S"
+        S="${p2[*]}"
+        S="${S// /, }"
+        printf "Player 2's deck: %s\n" "$S"
+        str="${p1[*]}  ${p2[*]}"
+
+        #[[ -v ${!hash[$_str]} ]] && return 1
+        if [[ -v hash["$str"] ]]; then
+            _res=1
+            return 1
+        fi
+        printf "Player 1 plays: %s\n" "$p1"
+        printf "Player 2 plays: %s\n" "$p2"
+        hash["$str"]=""
+
+        if ((p1 < ${#p1[@]} && p2 < ${#p2[@]} )); then
+            sp1=(${p1[*]:1:p1})
+            sp2=(${p2[*]:1:p2})
+            printf "Playing a sub-game to determine the winner...\n"
+            run winner sp1 sp2
+            winner=$?
+            printf "...anyway, back to game %d.\n" "$g"
+        else
+            ((p1 > p2)) && winner=1 || winner=2
+        fi
+        if ((winner==1)); then
+            p1+=("$p1" "$p2")
+            _res=1
+            printf "Player 1 wins round %d of game %d!\n" "$round" "$g"
+        else
+            p2+=("$p2" "$p1")
+            _res=2
+            printf "Player 2 wins round %d of game %d!\n" "$round" "$g"
+        fi
+        p1=("${p1[@]:1}")
+        p2=("${p2[@]:1}")
+        #printf "   p1=%s\n" "${p1[*]}"
+        #printf "   p2=%s\n" "${p2[*]}"
+        ((round++))
+    done
+    _p1=(${p1[@]})
+    _p2=(${p2[@]})
+    _res="$winner"
+    printf "The winner of game %d is player %d!\n\n" "$g" "$_res"
+    return "$winner"
+}
+
+declare -i res
+run res CARDS1 CARDS2
+declare -i n=$((${#CARDS1[@]}+${#CARDS2[@]})) i
+res=0
+
+S="${CARDS1[*]}"
+S="${S// /, }"
+printf "Player 1's deck: %s\n" "$S"
+S="${CARDS2[*]}"
+S="${S// /, }"
+printf "Player 2's deck: %s\n" "$S"
+
+for i in "${CARDS1[@]}" "${CARDS2[@]}"; do
+    ((res+=n*i, n--))
+done
+
+printf "%s: res=%d (should be 32760)\n" "$CMD" "$res"
+exit 0