Started 2022 with go

2022/go/04/answer.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+type Range struct {
+	low, high int
+}
+
+func (r *Range) contians(other *Range) bool {
+	return r.low <= other.low && other.high <= r.high
+}
+
+func (r *Range) overlaps(other *Range) bool {
+	return (r.low <= other.low && other.low <= r.high) ||
+		(r.low <= other.high && other.high <= r.high)
+}
+
+func fromString(s string) Range {
+	parts := strings.Split(s, "-")
+	low, err := strconv.Atoi(parts[0])
+	check(err, "Can't convert %q to int", parts[0])
+	high, err := strconv.Atoi(parts[1])
+	check(err, "Can't convert %q to int", parts[1])
+	return Range{low, high}
+}
+
+type Input struct {
+	ranges []struct{ a, b Range }
+}
+
+func input(filename string) *Input {
+	file, err := os.Open(filename)
+	check(err, "Couldn't open %q", filename)
+	defer file.Close()
+
+	input := &Input{}
+
+	scanner := bufio.NewScanner(file)
+
+	scanner.Split(bufio.ScanLines)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		sets := strings.Split(line, ",")
+		input.ranges = append(input.ranges, struct{ a, b Range }{fromString(sets[0]), fromString(sets[1])})
+	}
+
+	return input
+}
+
+func result(inp *Input, part int8) string {
+	var res string
+	score := 0
+
+	for _, pair := range inp.ranges {
+		if part == 1 {
+			if pair.a.contians(&pair.b) || pair.b.contians(&pair.a) {
+				score++
+			}
+		} else {
+			if pair.a.overlaps(&pair.b) || pair.b.overlaps(&pair.a) {
+				score++
+			}
+		}
+	}
+
+	res = fmt.Sprint(score)
+	return res
+}
+
+func check(e error, msg string, vals ...any) {
+	if e != nil {
+		log.Printf("ERROR: "+msg, vals)
+		panic(e)
+	}
+}
+
+func main() {
+	result := result(input("sample1"), 1)
+
+	log.Println(result)
+	fmt.Println(result)
+}

2022/go/04/answer_test.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestInputSample1(t *testing.T) {
+	filename := "sample1"
+	expected := &Input{
+		ranges: []struct{ a, b Range }{
+			{Range{2, 4}, Range{6, 8}},
+			{Range{2, 3}, Range{4, 5}},
+			{Range{5, 7}, Range{7, 9}},
+			{Range{2, 8}, Range{3, 7}},
+			{Range{6, 6}, Range{4, 6}},
+			{Range{2, 6}, Range{4, 8}},
+		},
+	}
+	var got *Input = input(filename)
+
+	if !reflect.DeepEqual(expected, got) {
+		t.Errorf("input(%q) = %v, want %v", filename, got, expected)
+	}
+}
+
+func TestResult(t *testing.T) {
+	tests := []struct {
+		part     int8
+		filename string
+		expected string
+	}{
+		{1, "sample1", "2"},
+		{1, "input", "530"},
+
+		{2, "sample1", "4"},
+		{2, "input", "903"},
+	}
+
+	for _, test := range tests {
+		var got string = result(input(test.filename), test.part)
+
+		if got != test.expected {
+			t.Errorf("result = %q, want %q", got, test.expected)
+		}
+	}
+}

2022/go/04/go.mod

@@ -0,0 +1,3 @@
+module aoc/4
+
+go 1.20

2022/go/04/sample1

@@ -0,0 +1,6 @@
+2-4,6-8
+2-3,4-5
+5-7,7-9
+2-8,3-7
+6-6,4-6
+2-6,4-8