#!/bin/env tclsh

source lib.tcl
setup 7

puts {Part 1: Total of valid test lines}

proc op_search {ops targ cur rest} {
  # cursed, produces exprs of the form "$cur<op>$next == $targ || ..."
  set e1 {}
  foreach op $ops {
    lappend e1 [string cat {$cur} $op {$next == $targ}]
  }
  set e1 [join $e1 " || "]
  # cursed, produces exprs of the form "[_op_search $e1 $e2 $targ [expr {$cur<op>$next}] $rest] || ..."
  set e2 {}
  foreach op $ops {
    lappend e2 [string cat \
      {[_op_search $e1 $e2 $targ [expr } \
      [list [string cat {$cur} $op {$next}]] \
      {] $rest]}]
  }
  set e2 [join $e2 " || "]

  _op_search $e1 $e2 $targ $cur $rest
}
proc _op_search {e1 e2 targ cur rest} {
  set rest [lassign $rest next]
  if {$rest == {}} {
    expr $e1
  } else {
    expr $e2
  }
}

set test_total 0
set cat_test_total 0
foreach line $input {
  lassign [split $line :] targ nums
  set nums [lassign $nums first]
  if [op_search {{ + } { * }} $targ $first $nums] {
    incr test_total $targ
  }
  if [op_search {{ + } { * } {}} $targ $first $nums] {
    incr test_total $targ
  }
}

puts "Total: $test_total"

puts ""
puts {Part 2: Total of valid test lines with || operator}

puts "2: $"