138 lines
2.6 KiB
Go
138 lines
2.6 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 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 cupInList(cup int, cups []int) bool {
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for _, c := range cups {
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if c == cup {
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return true
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}
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}
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return false
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}
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func generateFullCupset(cups []int, totalCups int) []int {
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for i := len(cups); i < totalCups; i = i + 1 {
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cups = append(cups, i)
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}
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return cups
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}
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func findTargetCupIndex(cup int, cups []int) int {
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for i, c := range cups {
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if c == cup {
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return i
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}
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}
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return 0 // uh-oh
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}
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func step(cups []int) []int {
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cupCount := len(cups)
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currentCup := cups[0]
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removedCups := cups[1:4]
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newList := make([]int, 0, cupCount)
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newList = append([]int{cups[0]}, cups[4:]...)
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var targetCup int
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if currentCup == 1 {
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targetCup = cupCount
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} else {
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targetCup = currentCup - 1
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}
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for cupInList(targetCup, removedCups) {
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targetCup = targetCup - 1
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if targetCup == 0 {
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targetCup = cupCount
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}
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}
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tc := findTargetCupIndex(targetCup, newList)
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result := make([]int, 0, cupCount)
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result = append(result, newList[1:tc+1]...)
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result = append(result, removedCups...)
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result = append(result, newList[tc+1:]...)
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result = append(result, newList[0])
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return result
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}
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func runabout(cups []int) string {
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oneIndex := findTargetCupIndex(1, cups)
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result := ""
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for i := oneIndex + 1; i < len(cups); i = i + 1 {
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result = result + strconv.Itoa(cups[i])
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}
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for i := 0; i < len(cups[:oneIndex]); i = i + 1 {
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result = result + strconv.Itoa(cups[i])
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}
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return result
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}
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func nextTwo(cups []int) (int, int) {
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oneIndex := findTargetCupIndex(1, cups)
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if oneIndex+1 > len(cups) {
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return cups[0], cups[1]
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}
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if oneIndex+2 > len(cups) {
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return cups[len(cups)], cups[0]
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}
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return cups[oneIndex+1], cups[oneIndex+2]
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}
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func partOne() {
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f, _ := os.Open("testinput")
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reader := bufio.NewReader(f)
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scanner := bufio.NewScanner(reader)
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cups := []int{}
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scanner.Scan()
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for _, s := range strings.Split(scanner.Text(), "") {
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i, _ := strconv.Atoi(s)
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cups = append(cups, i)
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}
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for i := 0; i < 100; i = i + 1 {
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cups = step(cups)
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}
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fmt.Println(runabout(cups))
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}
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func partTwo() {
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f, _ := os.Open("testinput")
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reader := bufio.NewReader(f)
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scanner := bufio.NewScanner(reader)
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cups := []int{}
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scanner.Scan()
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for _, s := range strings.Split(scanner.Text(), "") {
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i, _ := strconv.Atoi(s)
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cups = append(cups, i)
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}
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allCups := generateFullCupset(cups, 10000000)
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for i := 0; i < 10000000; i = i + 1 {
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allCups = step(allCups)
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fmt.Println(i)
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}
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fmt.Println(nextTwo(allCups))
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}
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