101 lines
1.6 KiB
Go
101 lines
1.6 KiB
Go
package main
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import (
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"aoc2024/helper"
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"fmt"
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"sort"
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)
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var reports [][]int
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func main() {
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reports = helper.ReadLinesToIntArrays()
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// part 1
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save_count := 0
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for _, r := range reports {
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if isReportSave(r) {
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save_count++
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}
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}
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fmt.Printf("Save reports: %d\n", save_count)
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// part 2
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save_count = 0
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for _, r := range reports {
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if isReportSaveWithDamper(r) {
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save_count++
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}
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}
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fmt.Printf("Save reports (with damper): %d\n", save_count)
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}
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func isReportSaveWithDamper(report []int) bool {
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if isReportSave(report) {
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return true
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}
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for i := range report {
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// remove one item from report and try to validate
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new_report := removeFromSlice(report, i)
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if isReportSave(new_report) {
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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 removeFromSlice(slice []int, dropIndex int) []int {
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var newslice []int
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for i, v := range slice {
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if i != dropIndex {
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newslice = append(newslice, v)
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}
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}
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return newslice
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}
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func isReportSave(report []int) bool {
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if !isReportSorted(report) {
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return false
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}
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for i := range report {
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if (i + 1) < len(report) {
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if !isPairSave(report[i], report[i+1]) {
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return false
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}
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}
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}
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return true
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}
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func isReportSorted(slice []int) bool {
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ascSorted := sort.SliceIsSorted(
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slice,
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func(i, j int) bool { return slice[i] < slice[j] },
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)
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descSorted := sort.SliceIsSorted(
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slice,
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func(i, j int) bool { return slice[i] > slice[j] },
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)
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return ascSorted || descSorted
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}
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func isPairSave(x int, y int) bool {
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if x == y {
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return false
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}
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diff := helper.Abs(x - y)
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if diff > 3 {
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return false
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}
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return true
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}
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