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author | Kartik K. Agaram <vc@akkartik.com> | 2021-07-16 08:09:42 -0700 |
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committer | Kartik K. Agaram <vc@akkartik.com> | 2021-07-16 08:28:56 -0700 |
commit | 44d26b77c45668c9b0c99894a4294cec004361fe (patch) | |
tree | 68a5dcd4971873efd4ce184e9bf9a531c2161813 /linux/apps/advent2020/1b.mu | |
parent | ac45f097153afd3a89f43886e4124c5b2c26b98a (diff) | |
download | mu-44d26b77c45668c9b0c99894a4294cec004361fe.tar.gz |
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Diffstat (limited to 'linux/apps/advent2020/1b.mu')
-rw-r--r-- | linux/apps/advent2020/1b.mu | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/linux/apps/advent2020/1b.mu b/linux/apps/advent2020/1b.mu new file mode 100644 index 00000000..a99709b8 --- /dev/null +++ b/linux/apps/advent2020/1b.mu @@ -0,0 +1,113 @@ +# https://adventofcode.com/2020/day/1 +# +# To run (on Linux): +# $ git clone https://github.com/akkartik/mu +# $ cd mu +# $ ./translate apps/advent2020/1b.mu +# $ ./a.elf < input +# found +# 143 407 1470 +# 85555470 +# +# You'll need to register to download the 'input' file for yourself. + +fn main -> _/ebx: int { + # data structure + var numbers-storage: (array int 0x100) # 256 ints + var numbers/esi: (addr array int) <- address numbers-storage + var numbers-index/ecx: int <- copy 0 + # phase 1: parse each line from stdin and add it to numbers + { + var line-storage: (stream byte 0x100) # 256 bytes + var line/edx: (addr stream byte) <- address line-storage + { +#? print-string 0, "== iter\n" + # 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 + # convert line to int and append it to numbers + var n/eax: int <- parse-decimal-int-from-stream line +#? print-int32-decimal 0, n +#? print-string 0, "\n" + var dest/ebx: (addr int) <- index numbers, numbers-index + copy-to *dest, n + numbers-index <- increment +#? print-string 0, "== " +#? print-int32-decimal 0, numbers-index +#? print-string 0, "\n" + loop + } + } + # phase 2: for every pair of distinct numbers, check if the rest of the + # array has 2020-it + var i/edi: int <- copy 0 + { + compare i, numbers-index + break-if->= + # for j from i+1 to end + var j/edx: int <- copy i + j <- increment + { + compare j, numbers-index + break-if->= + { + compare i, j + break-if-= + var target/ebx: int <- copy 0x7e4 # 2020 + var src/edi: (addr int) <- index numbers, i + target <- subtract *src + var src2/ecx: (addr int) <- index numbers, j + target <- subtract *src2 + { + var found?/eax: boolean <- find-after numbers, j, target + compare found?, 0/false + break-if-= + print-string 0, "found\n" + print-int32-decimal 0, *src + print-string 0, " " + print-int32-decimal 0, *src2 + print-string 0, " " + print-int32-decimal 0, target + print-string 0, "\n" + target <- multiply *src + target <- multiply *src2 + print-int32-decimal 0, target + print-string 0, "\n" + return 0/success + } + } + j <- increment + loop + } + i <- increment + loop + } + return 1/not-found +} + +fn find-after _numbers: (addr array int), start: int, _target: int -> _/eax: boolean { + var numbers/esi: (addr array int) <- copy _numbers + var target/edi: int <- copy _target + var len/ecx: int <- length numbers + var i/eax: int <- copy start + i <- increment + { + compare i, len + break-if->= + var src/edx: (addr int) <- index numbers, i + # if *src == target, return true + compare *src, target + { + break-if-!= + return 1/true + } + i <- increment + loop + } + return 0/false +} |