Add back Day 1

2023/gareth/day01/day01.go

@@ -0,0 +1,61 @@
+package day01
+
+import (
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+func Part1(input string) int {
+	total := 0
+	lines := strings.Split(input, "\r\n")
+	for _, line := range lines {
+		regex := regexp.MustCompile("[a-zA-Z]")
+		numbers := regex.ReplaceAllString(line, "")
+		number := string(numbers[0]) + string(numbers[len(numbers)-1])
+		i, _ := strconv.Atoi(number)
+		total += i
+	}
+
+	return total
+}
+
+func Part2(input string) int {
+	values := map[string]string{
+		"one":   "1",
+		"two":   "2",
+		"three": "3",
+		"four":  "4",
+		"five":  "5",
+		"six":   "6",
+		"seven": "7",
+		"eight": "8",
+		"nine":  "9",
+	}
+	lines := strings.Split(input, "\r\n")
+	s := ""
+
+	total := 0
+	for _, line := range lines {
+		numbers := []string{}
+		for _, c := range line {
+			s = s + string(c)
+			if num, err := strconv.Atoi(string(c)); err == nil {
+				numbers = append(numbers, strconv.Itoa(num))
+				s = ""
+			}
+			for key, value := range values {
+				if strings.Contains(s, key) {
+					numbers = append(numbers, value)
+					buffer := s[len(s)-1]
+					s = "" + string(buffer)
+				}
+			}
+		}
+		number := numbers[0] + numbers[len(numbers)-1]
+		i, _ := strconv.Atoi(number)
+		total += i
+		s = ""
+	}
+	return total
+}