From 93b22b966fd2a01eb109b7f8791568a77965be45 Mon Sep 17 00:00:00 2001
From: Alex Karle <alex@alexkarle.com>
Date: Fri, 29 Nov 2024 02:23:23 +0100
Subject: [PATCH] 2023: Add day 1 in go

Prepping for 2024!
---
 2023/.gitignore    |  3 +++
 2023/01/1.go       | 42 ++++++++++++++++++++++++++++++++++++++++++
 2023/01/2.go       | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2023/01/go.mod     |  3 +++
 2023/01/sample.txt |  7 +++++++
 5 files changed, 131 insertions(+)
 create mode 100644 2023/.gitignore
 create mode 100644 2023/01/1.go
 create mode 100644 2023/01/2.go
 create mode 100644 2023/01/go.mod
 create mode 100644 2023/01/sample.txt

diff --git a/2023/.gitignore b/2023/.gitignore
new file mode 100644
index 0000000..a09ab56
--- /dev/null
+++ b/2023/.gitignore
@@ -0,0 +1,3 @@
+# these are usually binaries if no extension
+1
+2
diff --git a/2023/01/1.go b/2023/01/1.go
new file mode 100644
index 0000000..0fa47da
--- /dev/null
+++ b/2023/01/1.go
@@ -0,0 +1,42 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"unicode"
+)
+
+func main() {
+	f, err := os.Open("input.txt")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer f.Close()
+
+	sum := 0
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := scanner.Text()
+		first := -1
+		last := -1
+		for _, c := range line {
+			if unicode.IsNumber(c) {
+				n := int(c - '0')
+				if first == -1 {
+					first = n
+					last = n
+				} else {
+					last = n
+				}
+			}
+		}
+		sum += 10*first + last
+	}
+	fmt.Println(sum)
+
+	if err := scanner.Err(); err != nil {
+		log.Fatal(err)
+	}
+}
diff --git a/2023/01/2.go b/2023/01/2.go
new file mode 100644
index 0000000..7e76c6c
--- /dev/null
+++ b/2023/01/2.go
@@ -0,0 +1,76 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"regexp"
+	"strconv"
+)
+
+func getNum(s string) int {
+	switch s {
+	case "one":
+		return 1
+	case "two":
+		return 2
+	case "three":
+		return 3
+	case "four":
+		return 4
+	case "five":
+		return 5
+	case "six":
+		return 6
+	case "seven":
+		return 7
+	case "eight":
+		return 8
+	case "nine":
+		return 9
+	default:
+		n, err := strconv.Atoi(s)
+		if err != nil {
+			return -1
+		}
+		return n
+	}
+}
+
+func parseLine(line string) (int, int) {
+	firstRe := regexp.MustCompile("([0-9]|one|two|three|four|five|six|seven|eight|nine)")
+	lastRe := regexp.MustCompile(".*([0-9]|one|two|three|four|five|six|seven|eight|nine)")
+	first := getNum(firstRe.FindStringSubmatch(line)[1])
+	last := getNum(lastRe.FindStringSubmatch(line)[1])
+
+	return first, last
+}
+
+func main() {
+	fname := "input.txt"
+	if len(os.Args) > 1 {
+		fname = os.Args[1]
+	}
+	f, err := os.Open(fname)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer f.Close()
+
+	sum := 0
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := scanner.Text()
+		first, last := parseLine(line)
+		if os.Getenv("DEBUG") != "" {
+			fmt.Println(10*first + last)
+		}
+		sum += 10*first + last
+	}
+	fmt.Println(sum)
+
+	if err := scanner.Err(); err != nil {
+		log.Fatal(err)
+	}
+}
diff --git a/2023/01/go.mod b/2023/01/go.mod
new file mode 100644
index 0000000..15f71cc
--- /dev/null
+++ b/2023/01/go.mod
@@ -0,0 +1,3 @@
+module alexkarle.com/aoc-2023-d1
+
+go 1.23.1
diff --git a/2023/01/sample.txt b/2023/01/sample.txt
new file mode 100644
index 0000000..41aa89c
--- /dev/null
+++ b/2023/01/sample.txt
@@ -0,0 +1,7 @@
+two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen
--
libgit2 1.8.1