first commit

.gitignore

@@ -0,0 +1,29 @@
+# If you prefer the allow list template instead of the deny list, see community template:
+# https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore
+#
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
+# Go workspace file
+go.work
+go.work.sum
+
+# env file
+.env
+
+# input files
+partial.txt
+input.txt

day-01/go.mod

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+module github.com/onyx-and-iris/aoc2024/day-01
+
+go 1.23.3

day-01/internal/one/solve.go

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+package one
+
+import (
+	"bufio"
+	"bytes"
+	"embed"
+	"io"
+	"math"
+	"regexp"
+
+	"github.com/onyx-and-iris/aoc2024/day-01/internal/util"
+)
+
+//go:embed testdata
+var files embed.FS
+
+var reNums = regexp.MustCompile(`[0-9]+`)
+
+func Solve() (int, error) {
+	data, _ := files.ReadFile("testdata/input.txt")
+
+	r := bytes.NewReader(data)
+	left, right, err := parseLines(r)
+	if err != nil {
+		return 0, err
+	}
+
+	var sum int
+	for i, n := range left {
+		sum += int(math.Abs(float64(n - right[i])))
+	}
+	return sum, nil
+}
+
+func parseLines(r io.Reader) ([]int, []int, error) {
+	var left, right []int
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		nums := reNums.FindAllString(scanner.Text(), -1)
+		left = util.InsertSorted(left, util.MustConv(nums[0]))
+		right = util.InsertSorted(right, util.MustConv(nums[1]))
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, nil, err
+	}
+
+	return left, right, nil
+}

day-01/internal/two/solve.go

@@ -0,0 +1,63 @@
+package two
+
+import (
+	"bufio"
+	"bytes"
+	"embed"
+	"io"
+	"regexp"
+	"slices"
+
+	"github.com/onyx-and-iris/aoc2024/day-01/internal/util"
+)
+
+//go:embed testdata
+var files embed.FS
+
+var reNums = regexp.MustCompile(`[0-9]+`)
+
+func Solve() (int, error) {
+	data, _ := files.ReadFile("testdata/input.txt")
+
+	r := bytes.NewReader(data)
+	left, right, err := parseLines(r)
+	if err != nil {
+		return 0, err
+	}
+
+	var similarity int
+	for k, v := range left {
+		indx := slices.Index(right, k)
+		if indx == -1 {
+			continue
+		}
+
+		var occurrences int
+		for _, n := range right[indx:] {
+			if n == k {
+				occurrences++
+			}
+		}
+		similarity += k * v * occurrences
+	}
+
+	return similarity, nil
+}
+
+func parseLines(r io.Reader) (map[int]int, []int, error) {
+	var left map[int]int = make(map[int]int)
+	var right []int
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		nums := reNums.FindAllString(scanner.Text(), -1)
+		left[util.MustConv(nums[0])] = left[util.MustConv(nums[0])] + 1
+		right = util.InsertSorted(right, util.MustConv(nums[1]))
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, nil, err
+	}
+
+	return left, right, nil
+}

day-01/internal/util/util.go

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+package util
+
+import (
+	"cmp"
+	"slices"
+	"strconv"
+)
+
+func MustConv(s string) int {
+	n, err := strconv.Atoi(s)
+	if err != nil {
+		panic(err)
+	}
+	return n
+}
+
+func InsertSorted[T cmp.Ordered](ts []T, t T) []T {
+	i, _ := slices.BinarySearch(ts, t)
+	return slices.Insert(ts, i, t)
+}

day-01/main.go

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+/********************************************************************************
+    Advent of Code 2024 - day-01
+********************************************************************************/
+
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/onyx-and-iris/aoc2024/day-01/internal/one"
+	"github.com/onyx-and-iris/aoc2024/day-01/internal/two"
+)
+
+func main() {
+	val, err := one.Solve()
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("solution one: %d\n", val)
+
+	val, err = two.Solve()
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Printf("solution two: %d\n", val)
+}

day-01/makefile

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+program = day-01
+
+GO = go
+SRC_DIR := src
+BIN_DIR := bin
+
+EXE := $(BIN_DIR)/$(program)
+
+.DEFAULT_GOAL := build
+
+.PHONY: fmt vet build clean
+fmt:        
+	$(GO) fmt ./...
+
+vet: fmt        
+	$(GO) vet ./...
+
+build: vet | $(BIN_DIR)
+	$(GO) build -o $(EXE) .
+
+$(BIN_DIR):
+	@mkdir -p $@
+
+clean:
+	@rm -rv $(BIN_DIR)

scaffold.sh

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+#!/usr/bin/env bash
+
+name=day-"$1"
+
+if [ -d day-"$name" ]; then
+    echo "program $name already exists"
+    exit 1
+fi
+
+mkdir -p "$name"/testdata
+touch "$name"/makefile
+
+cat <<EOT >> "$name"/makefile
+program = $name
+
+GO = go
+SRC_DIR := src
+BIN_DIR := bin
+
+EXE := \$(BIN_DIR)/\$(program)
+
+.DEFAULT_GOAL := build
+
+.PHONY: fmt vet build clean
+fmt:        
+	\$(GO) fmt ./...
+
+vet: fmt        
+	\$(GO) vet ./...
+
+build: vet | \$(BIN_DIR)
+	\$(GO) build -o \$(EXE) ./\$(SRC_DIR)
+
+\$(BIN_DIR):
+	@mkdir -p \$@
+
+clean:
+	@rm -rv \$(BIN_DIR)
+EOT
+
+cat <<EOT >> "$name"/solution.go
+/********************************************************************************
+    Advent of Code 2024 - $name
+********************************************************************************/
+
+package main
+
+func main() {
+    
+}
+EOT
+
+cd "$name" || exit
+
+go mod init github.com/onyx-and-iris/aoc2024/"$name"