146 lines
2.8 KiB
Go
146 lines
2.8 KiB
Go
package main
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import (
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"bufio"
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"fmt"
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"os"
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"strconv"
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"strings"
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"time"
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)
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func must[T, Q any](f func(T) (Q, error), t T) Q {
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q, err := f(t)
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if err != nil {
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panic(err)
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}
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return q
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}
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func iter[T, Q any](f func(T) Q, t []T) []Q {
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r := make([]Q, len(t))
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for i := 0; i < len(t); i++ {
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r[i] = f(t[i])
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}
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return r
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}
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func main() {
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start := time.Now()
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partOne()
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duration := time.Since(start)
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partTwo()
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duration2 := time.Since(start)
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fmt.Printf("p1: %s, p2: %s\n", duration, duration2-duration)
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}
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func makeScanner(test bool) *bufio.Scanner {
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var f *os.File
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if test {
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f, _ = os.Open("inputs/testinput")
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} else {
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f, _ = os.Open("inputs/input")
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}
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reader := bufio.NewReader(f)
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return bufio.NewScanner(reader)
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}
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func partOne() {
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scanner := makeScanner(false)
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seeds := [][]int{}
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scanner.Scan()
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line := scanner.Text()
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_, seedList, _ := strings.Cut(line, ": ")
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for _, s := range strings.Split(seedList, " ") {
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seeds = append(seeds, []int{must(strconv.Atoi, s)})
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}
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scanner.Scan() // discard empty line
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state := 1
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for scanner.Scan() {
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line := scanner.Text()
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if line == "" {
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for i, s := range seeds {
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if len(s) == state {
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seeds[i] = append(seeds[i], s[state-1])
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}
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}
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state++
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continue
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}
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if line[len(line)-1] == ':' {
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continue
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}
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// destination, source, length
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m := iter(
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func(s string) int { return must(strconv.Atoi, s) },
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strings.Split(line, " "),
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)
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for i, s := range seeds {
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if len(s) == state && m[1] <= s[state-1] && m[1]+m[2] > s[state-1] {
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seeds[i] = append(seeds[i], s[state-1]-m[1]+m[0])
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}
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}
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}
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lowest := seeds[0][len(seeds[0])-1]
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for _, s := range seeds {
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if s[len(s)-1] < lowest {
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lowest = s[len(s)-1]
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}
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}
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fmt.Println(lowest)
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}
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func partTwo() {
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scanner := makeScanner(true)
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seeds := [][]int{}
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scanner.Scan()
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line := scanner.Text()
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_, seedRanges, _ := strings.Cut(line, ": ")
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r := strings.Split(seedRanges, " ")
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for i := 0; i <= len(r); i += i + 2 {
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rng := must(strconv.Atoi, r[i+1])
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for j := 0; j < rng; j++ {
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// this is too slow!
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seeds = append(seeds, []int{must(strconv.Atoi, r[i]) + j})
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}
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}
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scanner.Scan() // discard empty line
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state := 1
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for scanner.Scan() {
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line := scanner.Text()
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if line == "" {
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for i, s := range seeds {
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if len(s) == state {
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seeds[i] = append(seeds[i], s[state-1])
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}
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}
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state++
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continue
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}
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if line[len(line)-1] == ':' {
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continue
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}
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// destination, source, length
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m := iter(
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func(s string) int { return must(strconv.Atoi, s) },
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strings.Split(line, " "),
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)
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for i, s := range seeds {
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if len(s) == state && m[1] <= s[state-1] && m[1]+m[2] > s[state-1] {
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seeds[i] = append(seeds[i], s[state-1]-m[1]+m[0])
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}
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}
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}
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lowest := seeds[0][len(seeds[0])-1]
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for _, s := range seeds {
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if s[len(s)-1] < lowest {
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lowest = s[len(s)-1]
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}
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}
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fmt.Println(lowest)
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}
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