87 lines
1.8 KiB
Go
87 lines
1.8 KiB
Go
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package main
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import (
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"fmt"
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"os"
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"strings"
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"strconv"
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"github.com/thoas/go-funk"
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)
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func check(e error) {
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if e != nil { panic(e) }
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}
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func abs(n int) int {
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if n < 0 { return -n }
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return n
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}
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func pop(arr []int, idx int) []int {
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out := make([]int, len(arr) - 1)
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for i, elem := range arr {
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if i == idx {
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continue
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} else if i > idx {
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out[i - 1] = elem
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} else {
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out[i] = elem
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}
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}
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return out
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}
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func change(s []int) []int {
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out := make([]int, len(s) - 1)
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for i := range out {
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out[i] = s[i + 1] - s[i]
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}
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return out
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}
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func validate_change(change []int) bool {
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all_neg := len( funk.Filter(change, func(x int) bool { return x >= 0 }).([]int) ) == 0
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all_pos := len( funk.Filter(change, func(x int) bool { return x <= 0 }).([]int) ) == 0
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all_abs_lt_4 := len( funk.Filter(change, func(x int) bool { return abs(x) > 3 }).([]int) ) == 0
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return ( all_neg || all_pos ) && all_abs_lt_4
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}
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func main() {
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// read in file as lines
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dat, err := os.ReadFile("data.txt")
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check(err)
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valid := 0
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lines := strings.Split(string(dat), "\n")
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// for every non empty line
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for _, line := range lines {
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if line == "" { continue }
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// get numbers as array
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str_levels := strings.Split(line, " ")
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// convert to integer
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levels := make([]int, len(str_levels))
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for j := range str_levels {
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levels[j], err = strconv.Atoi(str_levels[j])
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check(err)
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}
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// check for valid series
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for i := range levels {
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slice := pop(levels, i)
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if validate_change(change(slice)) {
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valid++
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break
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}
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}
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}
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fmt.Println(valid)
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}
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