Started AOC 2020 - solved the first 4.5 days.

2020/day04.go

@@ -0,0 +1,153 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"git.annabunch.es/annabunches/adventofcode/2020/lib/fileutils"
+)
+
+func splitPassports(input []string) []string {
+	converted := []string{}
+
+	current := ""
+	for _, line := range input {
+		if line == "" {
+			converted = append(converted, current)
+			current = ""
+			continue
+		}
+
+		current += " " + line
+	}
+
+	return converted
+}
+
+func countValidPassports(input []string, step string) int {
+	total := 0
+	for _, line := range input {
+		if strings.Contains(line, "byr:") &&
+			strings.Contains(line, "iyr:") &&
+			strings.Contains(line, "eyr:") &&
+			strings.Contains(line, "hgt:") &&
+			strings.Contains(line, "hcl:") &&
+			strings.Contains(line, "ecl:") &&
+			strings.Contains(line, "pid:") {
+			if step == "1" {
+				total += 1
+				continue
+			}
+
+			i := validatePassport(line)
+			if i == 0 {
+				log.Printf("Failed: %s", line)
+			} else {
+				log.Printf("Passed: %s", line)
+			}
+
+			total += i
+		}
+	}
+
+	return total
+}
+
+func validatePassport(input string) int {
+	fields := strings.Split(input, " ")
+	for _, field := range fields {
+		if field == "" {
+			continue
+		}
+
+		subFields := strings.Split(field, ":")
+		if len(subFields) != 2 {
+			log.Panicf("Failed to split subfields on '%s'", field)
+		}
+		name := subFields[0]
+		value := subFields[1]
+
+		switch name {
+		case "byr":
+			ivalue := makeInt(value)
+			if ivalue < 1920 || ivalue > 2002 {
+				return 0
+			}
+		case "iyr":
+			ivalue := makeInt(value)
+			if ivalue < 2010 || ivalue > 2020 {
+				return 0
+			}
+		case "eyr":
+			ivalue := makeInt(value)
+			if ivalue < 2020 || ivalue > 2030 {
+				return 0
+			}
+		case "hgt":
+			if strings.HasSuffix(value, "cm") {
+				ivalue := makeInt(strings.TrimSuffix(value, "cm"))
+				if ivalue < 150 || ivalue > 193 {
+					return 0
+				}
+			} else if strings.HasSuffix(value, "in") {
+				ivalue := makeInt(strings.TrimSuffix(value, "in"))
+				if ivalue < 59 || ivalue > 76 {
+					return 0
+				}
+			} else {
+				return 0
+			}
+		case "hcl":
+			match, err := regexp.MatchString("^#[0-9a-f]{6}$", value)
+			if err != nil {
+				log.Panicf(err.Error())
+			}
+			if !match {
+				return 0
+			}
+		case "ecl":
+			if value != "amb" &&
+				value != "blu" &&
+				value != "brn" &&
+				value != "gry" &&
+				value != "grn" &&
+				value != "hzl" &&
+				value != "oth" {
+				return 0
+			}
+		case "pid":
+			match, err := regexp.MatchString("^[0-9]{9}$", value)
+			if err != nil {
+				log.Panicf(err.Error())
+			}
+			if !match {
+				return 0
+			}
+		case "cid":
+		default:
+			log.Panicf("Got bad field data: ")
+		}
+	}
+
+	return 1
+}
+
+func makeInt(input string) int {
+	i, err := strconv.Atoi(input)
+	if err != nil {
+		log.Panicf(err.Error())
+	}
+	return i
+}
+
+func main() {
+	step := os.Args[1]
+	values := fileutils.InputParserStrings(os.Args[2])
+	values = splitPassports(values)
+
+	fmt.Println("Valid Passports:", countValidPassports(values, step))
+}