feat: y2023

helpers/maths.go

@@ -13,6 +13,18 @@ func MaxInts(ints []int) int {
 	return max
 }
 
+func MinInts(ints []int) int {
+	min := ints[0]
+
+	for _, i := range ints {
+		if i < min {
+			min = i
+		}
+	}
+
+	return min
+}
+
 // Find the GCD of two integers.
 func GCD(a, b int) int {
 	if a < 0 {

y2023/d01/fabienz/solution.go

@@ -0,0 +1,150 @@
+package fabienz
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/fabienzucchet/adventofcode/helpers"
+)
+
+// PartOne solves the first problem of day 1 of Advent of Code 2023.
+func PartOne(input io.Reader, answer io.Writer) error {
+	// Read the input. Feel free to change it depending on the input.
+	lines, err := helpers.LinesFromReader(input)
+	if err != nil {
+		return fmt.Errorf("could not read input: %w", err)
+	}
+
+	sum := 0
+
+	for _, line := range lines {
+		first, last, err := findFirstAndLastDigit(line)
+		if err != nil {
+			return fmt.Errorf("could not find first and last digit: %w", err)
+		}
+
+		sum += 10*first + last
+	}
+
+	_, err = fmt.Fprintf(answer, "%d", sum)
+	if err != nil {
+		return fmt.Errorf("could not write answer: %w", err)
+	}
+
+	return nil
+}
+
+// PartTwo solves the second problem of day 1 of Advent of Code 2023.
+func PartTwo(input io.Reader, answer io.Writer) error {
+	// Read the input. Feel free to change it depending on the input.
+	lines, err := helpers.LinesFromReader(input)
+	if err != nil {
+		return fmt.Errorf("could not read input: %w", err)
+	}
+
+	sum := 0
+
+	for _, line := range lines {
+		first, last, err := findFirstAndLastDigitWithWords(line)
+		if err != nil {
+			return fmt.Errorf("could not find first and last digit: %w", err)
+		}
+
+		sum += 10*first + last
+	}
+
+	_, err = fmt.Fprintf(answer, "%d", sum)
+	if err != nil {
+		return fmt.Errorf("could not write answer: %w", err)
+	}
+
+	return nil
+}
+
+// Returns the first and last digit of a string.
+func findFirstAndLastDigit(s string) (first int, last int, err error) {
+	first, last = -1, -1
+
+	for i := 0; i < len(s); i++ {
+		if isDigit(rune(s[i])) {
+			if first == -1 {
+				first, err = toDigit(rune(s[i]))
+				if err != nil {
+					return -1, -1, fmt.Errorf("could not convert first digit: %w", err)
+				}
+			}
+
+			last, err = toDigit(rune(s[i]))
+			if err != nil {
+				return -1, -1, fmt.Errorf("could not convert last digit: %w", err)
+			}
+		}
+	}
+
+	return first, last, nil
+}
+
+// Checks if a rune is a digit.
+func isDigit(r rune) bool {
+	return r >= '0' && r <= '9'
+}
+
+// Converts a digit rune to an integer.
+func toDigit(r rune) (int, error) {
+	d := int(r - '0')
+
+	if d < 0 {
+		return 0, fmt.Errorf("rune %q is not a digit", r)
+	}
+
+	return d, nil
+}
+
+// Find the first and last digit also checking words.
+func findFirstAndLastDigitWithWords(s string) (first int, last int, err error) {
+	first, last = -1, -1
+
+	for i, r := range s {
+		if isDigit(r) {
+			if first == -1 {
+				first, err = toDigit(r)
+				if err != nil {
+					return -1, -1, fmt.Errorf("could not convert first digit: %w", err)
+				}
+			}
+
+			last, err = toDigit(r)
+			if err != nil {
+				return -1, -1, fmt.Errorf("could not convert last digit: %w", err)
+			}
+
+			continue
+		}
+
+		for word, digit := range wordsToDigits {
+			if strings.HasPrefix(s[i:], word) {
+				if first == -1 {
+					first = digit
+				}
+
+				last = digit
+			}
+		}
+
+	}
+
+	return first, last, nil
+}
+
+var wordsToDigits = map[string]int{
+	"one":   1,
+	"two":   2,
+	"three": 3,
+	"four":  4,
+	"five":  5,
+	"six":   6,
+	"seven": 7,
+	"eight": 8,
+	"nine":  9,
+}

y2023/d01/fabienz/solution_test.go

@@ -0,0 +1,58 @@
+package fabienz
+
+import (
+	"log"
+	"os"
+	"testing"
+
+	"github.com/fabienzucchet/adventofcode/helpers"
+)
+
+func ExamplePartOne() {
+	file, err := os.Open("testdata/input.txt")
+	if err != nil {
+		log.Fatalf("could not open input file: %v", err)
+	}
+	defer file.Close()
+
+	if err := PartOne(file, os.Stdout); err != nil {
+		log.Fatalf("could not solve: %v", err)
+	}
+	// Output: 54239
+}
+
+func ExamplePartTwo() {
+	file, err := os.Open("testdata/input.txt")
+	if err != nil {
+		log.Fatalf("could open input file: %v", err)
+	}
+	defer file.Close()
+
+	if err := PartTwo(file, os.Stdout); err != nil {
+		log.Fatalf("could not solve: %v", err)
+	}
+	// Output: 55343
+}
+
+func Benchmark(b *testing.B) {
+	testCases := map[string]struct {
+		solution  helpers.Solution
+		inputFile string
+	}{
+		"PartOne": {
+			solution:  helpers.SolutionFunc(PartOne),
+			inputFile: "testdata/input.txt",
+		},
+
+		"PartTwo": {
+			solution:  helpers.SolutionFunc(PartTwo),
+			inputFile: "testdata/input.txt",
+		},
+	}
+
+	for name, test := range testCases {
+		b.Run(name, func(b *testing.B) {
+			helpers.BenchmarkSolution(b, test.solution, test.inputFile)
+		})
+	}
+}