96 lines
1.4 KiB
Go
96 lines
1.4 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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)
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func IntAbs(a int) int {
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if a >= 0 {
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return a
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}
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return -a
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}
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func main() {
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lists := readData("data.txt")
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fmt.Println(doTheThing(lists, 0))
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fmt.Println(doTheThing(lists, 1))
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}
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func readData(fileName string) (list [][]int) {
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fp, err := os.Open(fileName)
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if err != nil {
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panic(err)
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}
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scanner := bufio.NewScanner(fp)
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list = make([][]int, 0)
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for scanner.Scan() {
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line := strings.TrimSpace(scanner.Text())
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sublist := make([]int, 0)
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for _, n := range strings.Split(line, " ") {
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value, err := strconv.Atoi(n)
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if err != nil {
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panic(err)
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}
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sublist = append(sublist, value)
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}
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list = append(list, sublist)
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}
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return
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}
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func doTheThing(list [][]int, canSkip int) (valid int) {
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for _, l := range list {
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if isValid(l, canSkip, -1) {
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valid += 1
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}
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}
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return
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}
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func isValid(l []int, canSkip int, toSkip int) bool {
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sumDiff := 0
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sumAbsDiff := 0
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for i := 0; i < len(l)-1; i++ {
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if i == toSkip {
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continue
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}
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j := i + 1
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if j == toSkip {
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j += 1
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if j >= len(l) {
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continue
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}
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}
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diff := l[i] - l[j]
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if diff == 0 || IntAbs(diff) > 3 || IntAbs(sumDiff+diff) != sumAbsDiff+IntAbs(diff) {
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if canSkip > 0 {
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return isValid(l, canSkip-1, i-1) || isValid(l, canSkip-1, i) || isValid(l, canSkip-1, j)
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} else {
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return false
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}
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}
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sumDiff += diff
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sumAbsDiff += IntAbs(diff)
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}
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return true
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}
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