day5/computer.sh

   1 #!/bin/bash
   2
   3 exec 3<input.txt
   4
   5 OLDIFS=$IFS
   6 IFS="," read -u 3 -a orig_data
   7 IFS=$OLDIFS
   8
   9 run_program() {
  10     data=("${orig_data[@]}")
  11     pos=0
  12     declare -a immediate
  13     while [ $pos -le ${#data[@]} ]; do
  14         loc1=${data[$((pos+1))]}
  15         loc2=${data[$((pos+2))]}
  16         res_loc=${data[$((pos+3))]}
  17         # first, printf the value to 5 digits
  18         instruction=$(printf "%05d" ${data[$pos]})
  19         for (( a=0; a<3; a++ )); do
  20             immediate[$((3-a))]=${instruction:$a:1}
  21         done
  22         instruction=${instruction:3}
  23         param_count=3
  24         case $instruction in
  25             01|02)
  26                 # 01 - add, 02 multiply
  27                 symbol="+"
  28                 if [ $instruction == "02" ]; then
  29                     symbol="*"
  30                 fi
  31                 val1=${data[$((pos+1))]}
  32                 val2=${data[$((pos+2))]}
  33                 if [ ${immediate[1]} -eq 0 ]; then
  34                     val1=${data[$loc1]}
  35                 fi
  36                 if [ ${immediate[2]} -eq 0 ]; then
  37                     val2=${data[$loc2]}
  38                 fi
  39                 data[$res_loc]=$(($val1 $symbol $val2))
  40                 ;;
  41             03)
  42                 # 03 - read input
  43                 read -p "input: " input
  44                 res_loc=${data[$((pos+1))]}
  45                 data[$res_loc]=$input
  46                 param_count=1
  47                 ;;
  48             04)
  49                 # 04 - output
  50                 if [ ${immediate[1]} -eq 1 ]; then
  51                     echo ${data[$((pos+1))]}
  52                 else
  53                     res_loc=${data[$((pos+1))]}
  54                     echo ${data[$res_loc]}
  55                 fi
  56                 param_count=1
  57                 ;;
  58             05|06)
  59                 # 05 - jump-if-true, 06 - jump-if-false
  60                 val=${data[$((pos+1))]}
  61                 jumpto=${data[$((pos+2))]}
  62                 param_count=2
  63                 if [ ${immediate[1]} -eq 0 ]; then
  64                     val=${data[$val]}
  65                 fi
  66                 if [ ${immediate[2]} -eq 0 ]; then
  67                     jumpto=${data[$jumpto]}
  68                 fi
  69                 if ( [ $val -ne 0 ] && [ "$instruction" == "05" ] ) ||
  70                     ( [ $val -eq 0 ] && [ "$instruction" == "06" ] ); then
  71                     pos=$jumpto
  72                     continue
  73                 fi
  74                 ;;
  75             07|08)
  76                 # 07 - is less than, 08 - is equal
  77                 val1=${data[$((pos+1))]}
  78                 val2=${data[$((pos+2))]}
  79                 res_pos=${data[$((pos+3))]}
  80                 if [ ${immediate[1]} -eq 0 ]; then
  81                     val1=${data[$val1]}
  82                 fi
  83                 if [ ${immediate[2]} -eq 0 ]; then
  84                     val2=${data[$val2]}
  85                 fi
  86                 data[$res_pos]=0
  87                 if [ "$instruction" == "07" ]; then
  88                     if [ $val1 -lt $val2 ]; then
  89                         data[$res_pos]=1
  90                     fi
  91                 else
  92                     if [ $val1 -eq $val2 ]; then
  93                         data[$res_pos]=1
  94                     fi
  95                 fi
  96                 ;;
  97             99)
  98                 break
  99                 ;;
 100             *)
 101                 echo "Invalid opcode: $instruction at position $pos"
 102                 exit 1
 103         esac
 104         pos=$(($pos+$param_count+1))
 105     done
 106 }
 107
 108 echo "Part 1:"
 109 run_program