day09/computer.sh

   1 #!/bin/bash
   2
   3 declare -a data
   4
   5 get_value() {
   6     local -n da=$1
   7     local index=$2
   8
   9     if [ $index -lt 0 ]; then
  10         echo "Index negative, give up!"
  11         exit 2
  12     fi
  13
  14     if ! [ ${da[$index]+a} ]; then
  15         da[$index]=0
  16     fi
  17
  18     echo "${da[$index]}"
  19 }
  20
  21 get_param() {
  22     local -n dap=$1
  23     local pos=$2
  24     local mode=$3
  25     local relative_base=$4
  26
  27     loc=$(get_param_loc dap $pos $mode $relative_base)
  28
  29     get_value dap $loc
  30 }
  31
  32 get_param_loc() {
  33     local -n dapl=$1
  34     local pos=$2
  35     local mode=$3
  36     local relative_base=$4
  37
  38     case $mode in
  39         0)
  40             get_value dapl $pos
  41             ;;
  42         1)
  43             echo $pos
  44             ;;
  45         2)
  46             move_by=$(get_value dapl $pos)
  47             echo $((relative_base+$move_by))
  48             ;;
  49         *)
  50             echo "Unknown parameter mode: $mode"
  51             exit 2
  52             ;;
  53     esac
  54 }
  55
  56 run_program() {
  57     local -n od=$1
  58     local relative_base=0
  59     data=("${od[@]}")
  60     pos=0
  61     declare -a immediate
  62     while [ $pos -le ${#data[@]} ]; do
  63         # first, printf the value to 5 digits
  64         instruction=$(printf "%05d" ${data[$pos]})
  65         for (( a=0; a<3; a++ )); do
  66             immediate[$((3-a))]=${instruction:$a:1}
  67         done
  68         instruction=${instruction:3}
  69         param_count=3
  70         echo -n $'\r'"    "$'\r'$instruction >&2
  71         case $instruction in
  72             01|02)
  73                 # 01 - add, 02 multiply
  74                 symbol="+"
  75                 if [ $instruction == "02" ]; then
  76                     symbol="*"
  77                 fi
  78                 val1=$(get_param data $((pos+1)) ${immediate[1]} $relative_base)
  79                 val2=$(get_param data $((pos+2)) ${immediate[2]} $relative_base)
  80                 res_loc=$(get_param_loc data $((pos+3)) ${immediate[3]} $relative_base)
  81                 data[$res_loc]=$(($val1 $symbol $val2))
  82                 ;;
  83             03)
  84                 # 03 - read input
  85                 echo -n $'\r'"    "$'\r' >&2
  86                 read -p "input: " input
  87                 res_loc=$(get_param_loc data $((pos+1)) ${immediate[1]} $relative_base)
  88                 data[$res_loc]=$input
  89                 param_count=1
  90                 ;;
  91             04)
  92                 # 04 - output
  93                 val=$(get_param data $((pos+1)) ${immediate[1]} $relative_base)
  94                 echo -n $'\r'"    "$'\r' >&2
  95                 echo $val
  96                 param_count=1
  97                 ;;
  98             05|06)
  99                 # 05 - jump-if-true, 06 - jump-if-false
 100                 val=$(get_param data $((pos+1)) ${immediate[1]} $relative_base)
 101                 jumpto=$(get_param data $((pos+2)) ${immediate[2]} $relative_base)
 102                 param_count=2
 103                 if ( [ $val -ne 0 ] && [ "$instruction" == "05" ] ) ||
 104                     ( [ $val -eq 0 ] && [ "$instruction" == "06" ] ); then
 105                     pos=$jumpto
 106                     continue
 107                 fi
 108                 ;;
 109             07|08)
 110                 # 07 - is less than, 08 - is equal
 111                 val1=$(get_param data $((pos+1)) ${immediate[1]} $relative_base)
 112                 val2=$(get_param data $((pos+2)) ${immediate[2]} $relative_base)
 113                 res_pos=$(get_param_loc data $((pos+3)) ${immediate[3]} $relative_base)
 114                 data[$res_pos]=0
 115                 if [ "$instruction" == "07" ]; then
 116                     if [ $val1 -lt $val2 ]; then
 117                         data[$res_pos]=1
 118                     fi
 119                 else
 120                     if [ $val1 -eq $val2 ]; then
 121                         data[$res_pos]=1
 122                     fi
 123                 fi
 124                 ;;
 125             09)
 126                 # adjust relative base
 127                 param_count=1
 128                 val=$(get_param data $((pos+1)) ${immediate[1]} $relative_base)
 129                 relative_base=$((relative_base+$val))
 130                 ;;
 131             99)
 132                 break
 133                 ;;
 134             *)
 135                 echo "Invalid opcode: $instruction at position $pos"
 136                 exit 1
 137                 ;;
 138         esac
 139         pos=$(($pos+$param_count+1))
 140     done
 141     echo -n $'\r'"    "$'\r'
 142 }
 143