105 lines
2.4 KiB
Go
105 lines
2.4 KiB
Go
package main
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import (
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"bufio"
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"bytes"
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"fmt"
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"math"
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"os"
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"strconv"
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)
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func main() {
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numbers, err := readInput("input")
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if err != nil {
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fmt.Printf("Error encountered: %s", err)
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return
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}
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// Alright, I am going for the simplest and most (reasonably) computationally expensive solution
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// So like... Don't hate on me for this XD
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findMinMax := func(slice []int) (min int, max int) {
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min = slice[0]
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max = slice[0]
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for _, value := range slice {
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if value < min {
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min = value
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}
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if value > max {
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max = value
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}
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}
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return
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}
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min, max := findMinMax(numbers)
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leastFuel := math.MaxInt
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position := min
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for i := min; i < max; i++ {
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fuel, _ := calculateFuel(numbers, i)
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//fmt.Printf("For position %d fuel costs %d\n", i, fuel)
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if fuel < leastFuel {
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leastFuel = fuel
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position = i
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}
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}
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fmt.Printf("The least amount of fuel is: %d at position %d\n", leastFuel, position)
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}
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func calculateFuel(numbers []int, target int) (int, error) {
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totalFuel := 0
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// For position target, calculate fuel costs
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for i := 0; i < len(numbers); i++ {
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fuelCosts := 1
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for j := 0; j < int(math.Abs(float64(numbers[i]-target))); j++ {
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totalFuel += fuelCosts
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fuelCosts++
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}
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}
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return totalFuel, nil
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}
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func readInput(inputfile string) ([]int, error) {
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file, err := os.OpenFile(inputfile, 0, 0)
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if err != nil {
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return nil, err
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}
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defer file.Close()
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splitfunc := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
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nextIndex := bytes.IndexByte(data, ',')
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if nextIndex > 0 {
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// Returning the next position aka taking only the stuff up to nextIndex and slicing off everything else
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buffer := data[:nextIndex]
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// nextIndex plus 1 because index is at the comma, we want the next number
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return nextIndex + 1, bytes.TrimSpace(buffer), nil
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}
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// If we are at the end of the buffer, then return the entire buffer, but only if there is data
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if atEOF {
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if len(data) > 0 {
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return len(data), bytes.TrimSpace(data), nil
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}
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}
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// https://github.com/kgrz/reading-files-in-go/blob/master/comma-separated-string.go
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// For more info
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return 0, nil, nil
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}
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scanner := bufio.NewScanner(file)
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scanner.Split(splitfunc)
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numbers := make([]int, 0)
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for scanner.Scan() {
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number, err := strconv.Atoi(scanner.Text())
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if err != nil {
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fmt.Printf("Error converting string to integer\n")
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return nil, err
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}
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numbers = append(numbers, number)
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}
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return numbers, nil
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}
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