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# https://adventofcode.com/2020/day/4
#
# To run (on Linux):
# $ git clone https://github.com/akkartik/mu
# $ cd mu
# $ ./translate_mu apps/advent2020/4a.mu
# $ ./a.elf < input
#
# You'll need to register to download the 'input' file for yourself.
fn main -> _/ebx: int {
var curr-passport-field-count/esi: int <- copy 0
var valid-passport-count/edi: int <- copy 0
var line-storage: (stream byte 0x100) # 256 bytes
var line/ecx: (addr stream byte) <- address line-storage
var slice-storage: slice
var slice/edx: (addr slice) <- address slice-storage
$main:line-loop: {
# read line from stdin
clear-stream line
read-line-from-real-keyboard line
# if line is empty (not even a newline), quit
var done?/eax: boolean <- stream-empty? line
compare done?, 0 # false
break-if-!=
print-stream-to-real-screen line
# if line has just a newline, process passport
skip-chars-matching-whitespace line
var new-passport?/eax: boolean <- stream-empty? line
{
compare new-passport?, 0 # false
break-if-=
compare curr-passport-field-count, 7
{
break-if-!=
valid-passport-count <- increment
print-string 0, "=> "
print-int32-decimal 0, valid-passport-count
print-string 0, "\n"
}
curr-passport-field-count <- copy 0
loop $main:line-loop
}
$main:word-loop: {
next-word line, slice
var done?/eax: boolean <- slice-empty? slice
compare done?, 0 # false
break-if-!=
print-string 0, " "
print-slice-to-real-screen slice
# treat cid as optional
var optional?/eax: boolean <- slice-starts-with? slice, "cid:"
compare optional?, 0 # false
{
break-if-!=
# otherwise assume there are no invalid fields and no duplicate fields
curr-passport-field-count <- increment
print-string 0, " => "
print-int32-decimal 0, curr-passport-field-count
}
print-string 0, "\n"
loop
}
loop
}
# process final passport
compare curr-passport-field-count, 7
{
break-if-!=
valid-passport-count <- increment
}
print-int32-decimal 0, valid-passport-count
print-string 0, "\n"
return 0
}
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