20223 day1

2023/go/day01/day01.go

@@ -0,0 +1,116 @@
+package day01
+
+import (
+	"adventofcode2023/utils"
+	 "fmt"
+	"strings"
+)
+func Part1(input string) int {
+	num := 0
+	lines := strings.Split(input, "\n")
+	for _, line := range lines {
+		for i:=0;i<len(line);i++ {
+			if line[i] >= '0' && line[i] <= '9' {
+				num += utils.MustAtoi(string(line[i])) * 10
+				break;
+			}
+		}
+		for i:=len(line) - 1;i>=0;i-- {
+			if line[i] >= '0' && line[i] <= '9' {
+				num += utils.MustAtoi(string(line[i]))
+				break;
+			}
+		}
+	}
+	return num
+
+}
+
+
+func Part2(input string) int {
+	digits := make(map[string]string)
+	digits["one"] = "1"
+	digits["two"] = "2"
+	digits["three"] = "3"
+	digits["four"] = "4"
+	digits["five"] = "5"
+	digits["six"] = "6"
+	digits["seven"] = "7"
+	digits["eight"] = "8"
+	digits["nine"] = "9"
+
+	digits_backwards := make(map[string]string)
+	digits_backwards["eno"] = "1"
+	digits_backwards["owt"] = "2"
+	digits_backwards["eerht"] = "3"
+	digits_backwards["ruof"] = "4"
+	digits_backwards["evif"] = "5"
+	digits_backwards["xis"] = "6"
+	digits_backwards["neves"] = "7"
+	digits_backwards["thgie"] = "8"
+	digits_backwards["enin"] = "9"
+	
+	num := 0
+	found := false
+	lines := strings.Split(input, "\n")
+	for _, line := range lines {
+		for i:=0;i<len(line);i++ {
+			if line[i] >= '0' && line[i] <= '9' {
+				fmt.Println("first digit:", string(line[i]))
+				num += utils.MustAtoi(string(line[i])) * 10
+				found = true
+			}
+			if found { break;}
+			for key := range digits {
+				if strings.HasPrefix(line[i:], key) {
+					fmt.Println("first digit:", digits[key])
+					num += utils.MustAtoi(digits[key]) * 10
+					found = true
+				}
+				if found { break;}
+			}
+		}
+
+		found = false
+
+		reverse := reverseString(line)
+
+		for i:=0;i<len(reverse);i++ {
+			if reverse[i] >= '0' && reverse[i] <= '9' {
+				fmt.Println("last digit:", string(reverse[i]))
+				num += utils.MustAtoi(string(reverse[i]))
+				found = true
+			}
+			if found { break;}
+			for key := range digits_backwards {
+				if strings.HasPrefix(reverse[i:], key) {
+					fmt.Println("last digit:", digits_backwards[key])
+					num += utils.MustAtoi(digits_backwards[key])
+					found = true
+				}
+				if found { break;}
+			}
+		}
+		found = false
+
+	}
+	return num
+}
+
+func reverseString(input string) string {
+	// Convert the string to a rune slice
+	runes := []rune(input)
+
+	// Get the length of the rune slice
+	length := len(runes)
+
+	// Reverse the order of runes
+	for i, j := 0, length-1; i < j; i, j = i+1, j-1 {
+		runes[i], runes[j] = runes[j], runes[i]
+	}
+
+	// Convert the reversed rune slice back to a string
+	reversedString := string(runes)
+
+	return reversedString
+}

2023/go/day01/day01_test.go

@@ -0,0 +1,28 @@
+package day01
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1(
+`1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet`)
+	require.Equal(t, 142, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(
+`two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen`)
+	require.Equal(t, 281, r)
+}