Day 5: If You Give A Seed A Fertilizer

05/main.go

@@ -0,0 +1,164 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"math"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func parseFile(filename string) []string {
+	file, err := os.Open(filename)
+	if err != nil {
+		fmt.Printf("Could not open %q: %q\n", filename, err)
+		os.Exit(1)
+	}
+	defer file.Close()
+
+	var arr []string
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		t := scanner.Text()
+		arr = append(arr, t)
+	}
+	return arr
+}
+
+type gardenMap struct {
+	destination int
+	source      int
+	length      int
+}
+
+func strToIntArr(s string) []int {
+	s1 := strings.Split(s, " ")
+	var seeds []int
+	for _, v := range s1 {
+		n, err := strconv.Atoi(v)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+		seeds = append(seeds, n)
+	}
+	return seeds
+}
+
+func convertToGardenMap(input []string, line int) ([]gardenMap, int) {
+	var category []gardenMap
+	for line < len(input) && input[line] != "" {
+		arr := strToIntArr(input[line])
+		category = append(category, gardenMap{
+			destination: arr[0],
+			source:      arr[1],
+			length:      arr[2],
+		})
+		line++
+	}
+	return category, line
+}
+
+func parseInput(filename string) ([]int, [][]gardenMap) {
+	input := parseFile(filename)
+
+	s := strings.Split(input[0], ": ")
+	seeds := strToIntArr(s[1])
+	line := 3
+	var specs [][]gardenMap
+	for line < len(input) && input[line] != "" {
+		var category []gardenMap
+		category, line = convertToGardenMap(input, line)
+		specs = append(specs, category)
+		line += 2
+	}
+	return seeds, specs
+}
+
+func part1(filename string) int {
+	seed, specs := parseInput(filename)
+	answer := math.MaxInt64
+	for _, v := range seed {
+		mapping := v
+		for _, v1 := range specs {
+			for _, v2 := range v1 {
+				if v2.source <= mapping && mapping <= v2.source+v2.length {
+					mapping = mapping - v2.source + v2.destination
+					break
+				}
+			}
+		}
+		if mapping < answer {
+			answer = mapping
+		}
+	}
+	return answer
+}
+
+type point struct {
+	point  int
+	length int
+}
+
+func translate(seed point, garden []gardenMap) []point {
+	var newPoints []point
+	i := seed.point
+	for i < seed.point+seed.length {
+		var p point
+		var found bool
+		for _, v := range garden {
+			if v.source <= i && i < v.source+v.length {
+				end := min(seed.point+seed.length, v.source+v.length)
+				p = point{i + v.destination - v.source, end - i}
+				i = end
+				found = true
+				break
+			}
+		}
+		if !found {
+			p = seed
+			i = seed.point + seed.length
+		}
+		newPoints = append(newPoints, p)
+	}
+	return newPoints
+}
+
+func lowestLocationNumber(seeds []point, specs [][]gardenMap) int {
+	points := seeds
+	for _, garden := range specs {
+		var newPoints []point
+		for _, seed := range points {
+			p := translate(seed, garden)
+			newPoints = append(newPoints, p...)
+		}
+		points = newPoints
+	}
+	answer := math.MaxInt64
+	for _, v := range points {
+		if v.point < answer {
+			answer = v.point
+		}
+	}
+	return answer
+}
+
+func part2(filename string) int {
+	seed, specs := parseInput(filename)
+	var seeds []point
+	for i := 0; i < len(seed); i += 2 {
+		seeds = append(seeds, point{
+			point:  seed[i],
+			length: seed[i+1],
+		})
+	}
+	answer := math.MaxInt64
+	for _, v := range seeds {
+		num := lowestLocationNumber([]point{v}, specs)
+		if num < answer {
+			answer = num
+		}
+	}
+	return answer
+}

05/main_test.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestParts(t *testing.T) {
+	testFile := "testdata/input_test.txt"
+	got := part1(testFile)
+	want := 35
+	if got != want {
+		t.Fatalf("got %v want %v", got, want)
+	}
+	got2 := part2(testFile)
+	want2 := 46
+	if got2 != want2 {
+		t.Fatalf("got %v want %v", got2, want2)
+	}
+
+	fmt.Println("Running input.txt")
+	// actualFile := "testdata/input.txt"
+	// fmt.Println("Answer for part 1:", part1(actualFile))
+	// fmt.Println("Answer for part 2:", part2(actualFile))
+}

05/testdata/input_test.txt

@@ -0,0 +1,33 @@
+seeds: 79 14 55 13
+
+seed-to-soil map:
+50 98 2
+52 50 48
+
+soil-to-fertilizer map:
+0 15 37
+37 52 2
+39 0 15
+
+fertilizer-to-water map:
+49 53 8
+0 11 42
+42 0 7
+57 7 4
+
+water-to-light map:
+88 18 7
+18 25 70
+
+light-to-temperature map:
+45 77 23
+81 45 19
+68 64 13
+
+temperature-to-humidity map:
+0 69 1
+1 0 69
+
+humidity-to-location map:
+60 56 37
+56 93 4