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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: construct table of 2-sums
var two-sums-storage: (array int 0x10000) # 256 * 256 ints
var two-sums/edi: (addr array int) <- address two-sums-storage
var i/eax: 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 result-index/ebx: int <- copy 0x100
result-index <- multiply i
result-index <- add j
var dest/ebx: (addr int) <- index two-sums, result-index
var src/eax: (addr int) <- index numbers, i
var result/eax: int <- copy *src
var src2/edx: (addr int) <- index numbers, j
result <- add *src2
copy-to *dest, result
}
j <- increment
loop
}
i <- increment
loop
}
# phase 3: for each number in two-sums, check if 2020-it is in the rest of
# the array
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
}
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