AdventOfCode/2022/day6.scala

51 lines
1.3 KiB
Scala

import java.nio.file.Files
import java.nio.file.Paths
import scala.util.control.NonLocalReturns.*
// scala day6.jar 52.22s user 0.54s system 100% cpu 52.389 total
extension (s: String) def noDuplicates: Boolean =
var i = 0
while i < (s.length-1) do
val c = s(i)
var j = i + 1
while j < s.length do
if s(j) == c then return false
j += 1
i += 1
return true
def first_unique_run_for(line: String, num: Int, skip: Int = 0): Int = returning {
for i <- num.max(skip) until line.length do
if line.substring(i-num, i).noDuplicates then
throwReturn(i)
throwReturn(-1)
}
def first_unique_run_while(line: String, num: Int, skip: Int = 0): Int =
var i = num.max(skip)
while i < line.length do
if line.substring(i-num, i).toCharArray.distinct.size == num then
return i
i += 1
return -1
@main def main() =
val line = Files.readString(Paths.get("input/6")).strip
// do_once(line)
perf_test(line, 1000000)
def do_once(line: String) =
val four = first_unique_run_for(line, 4)
val fourteen = first_unique_run_for(line, 14, four)
println(four)
println(fourteen)
def perf_test(line: String, n: Int) =
var four = -1
var fourteen = -1
for i <- 1 to n do
four = first_unique_run_for(line, 4)
fourteen = first_unique_run_for(line, 14, four)
println(four)
println(fourteen)