Finished 1st day

Refactor digit parsing logic and improve variable names

day1/part2.go

@@ -1,15 +1,34 @@
 package main
 
 import (
-	"bufio"
 	"errors"
 	"fmt"
 	"io"
-	"log"
 	"os"
-	"regexp"
+	"strings"
 )
 
+var digitsMap = map[string]int{
+	"one":   1,
+	"two":   2,
+	"three": 3,
+	"four":  4,
+	"five":  5,
+	"six":   6,
+	"seven": 7,
+	"eight": 8,
+	"nine":  9,
+	"1":     1,
+	"2":     2,
+	"3":     3,
+	"4":     4,
+	"5":     5,
+	"6":     6,
+	"7":     7,
+	"8":     8,
+	"9":     9,
+}
+
 func readInput() string {
 	stdin, err := io.ReadAll(os.Stdin)
 
@@ -20,105 +39,43 @@ func readInput() string {
 	return str
 }
 
-func readFile() string {
-	file, err := os.ReadFile("input.txt")
-	if err != nil {
-		panic(err)
-	}
-	str := string(file)
-	return str
-}
-
-func readFileLineByLine() []string {
-	var lines []string
-	file, err := os.Open("input.txt")
-	if err != nil {
-		log.Fatal(err)
-	}
-	defer file.Close()
-
-	scanner := bufio.NewScanner(file)
-	// optionally, resize scanner's capacity for lines over 64K, see next example
-	for scanner.Scan() {
-		lines = append(lines, scanner.Text())
-	}
-
-	if err := scanner.Err(); err != nil {
-		log.Fatal(err)
-	}
-	return lines
-}
-
 func parseDigit(input string) (int, error) {
-	digits := map[string]int{
-		"one":   1,
-		"two":   2,
-		"three": 3,
-		"four":  4,
-		"five":  5,
-		"six":   6,
-		"seven": 7,
-		"eight": 8,
-		"nine":  9,
-		"1":     1,
-		"2":     2,
-		"3":     3,
-		"4":     4,
-		"5":     5,
-		"6":     6,
-		"7":     7,
-		"8":     8,
-		"9":     9,
-	}
-	i, ok := digits[input]
+	i, ok := digitsMap[input]
 	if ok == false {
 		return 0, errors.New("err")
 	}
 	return i, nil
 }
 
-// func addDStrings(input1 string, input2 string) string {
-// 	num1, err := parseDigit(input1)
-// 	if err != nil {
-// 		num1 = input1
-// 		log.Fatalln(err)
-// 	}
-// 	num2, err := parseDigit(input2)
-// 	if err != nil {
-// 		num2 = input2
-// 		log.Fatalln(err)
-// 	}
-// 	num_str := num1 + num2
-// 	println(num_str)
-// 	return num_str
-// }
+func getDigit(line string) []int {
+	digits := []int{}
+	for i, c := range line {
+		if dig, err := parseDigit(string(c)); err == nil {
+			digits = append(digits, dig)
+		} else {
+			for spelling, number := range digitsMap {
+				if strings.HasPrefix(line[i:], spelling) {
+					digits = append(digits, number)
+				}
+			}
+		}
+	}
+	return digits
+}
 
 func main() {
-	// lines := strings.Split(readFile(), "\n")
-	lines := readFileLineByLine()
-	re := regexp.MustCompile(`(one|two|three|four|five|six|seven|eight|nine|\d)`)
+	lines := strings.Split(readInput(), "\n")
 	var answer int
 	for _, l := range lines {
-		matches := re.FindAllString(l, -1)
-		matches_len := len(matches)
-		if matches_len == 0 {
-			break
+		matches := getDigit(l)
+		if len(matches) == 0 {
+			continue
 		}
 		first := matches[0]
-		last := matches[matches_len-1]
-		num_f, err := parseDigit(first)
-		if err != nil {
-			log.Fatalln(err)
-		}
-		num_l, err := parseDigit(last)
-		// num_str := addDStrings(first, last)
-		// num, err := strconv.Atoi(num_str)
-		if err != nil {
-			log.Fatalln(err)
-		}
-		num := (num_f * 10) + num_l
+		last := matches[len(matches)-1]
+		num := (first * 10) + last
 		answer = answer + num
-		fmt.Println(l, first, last, num)
+		// fmt.Println(l, first, last, num)
 	}
 	fmt.Println(answer)
 }