Refactor

2023/day01/part2.go → 2023/day01/day01.go

@@ -8,6 +8,30 @@ import (
 	"github.com/sunilbpandey/advent-of-code/utils/go/strutils"
 )
 
+//go:embed input.txt
+var content string
+
+func setDigits(d1, d2 *int, value int) {
+	if *d1 == -1 {
+		*d1 = value
+	}
+	*d2 = value
+}
+
+func Part1() string {
+	sum := 0
+	strutils.ForEachLine(content, func(_ int, line string) {
+		d1, d2 := -1, -1
+		for _, c := range line {
+			if unicode.IsDigit(c) {
+				setDigits(&d1, &d2, int(c-'0'))
+			}
+		}
+		sum += d1*10 + d2
+	})
+	return strconv.Itoa(sum)
+}
+
 func Part2() string {
 	names := []string{"one", "two", "three", "four", "five", "six", "seven", "eight", "nine"}
 	sum := 0

2023/day02/part1.go → 2023/day02/day02.go

@@ -56,3 +56,34 @@ func Part1() string {
 	})
 	return strconv.Itoa(sum)
 }
+
+func Part2() string {
+	sum := 0
+	strutils.ForEachLine(content, func(_ int, line string) {
+		if len(line) == 0 {
+			return
+		}
+
+		maxPerColor := map[string]int{
+			"red":   0,
+			"green": 0,
+			"blue":  0,
+		}
+
+		_, sets := parseLine(line)
+		for _, set := range sets {
+			for color, count := range set {
+				if count > maxPerColor[color] {
+					maxPerColor[color] = count
+				}
+			}
+		}
+
+		product := 1
+		for _, count := range maxPerColor {
+			product *= count
+		}
+		sum += product
+	})
+	return strconv.Itoa(sum)
+}

2023/day03/part2.go → 2023/day03/day03.go

@@ -1,6 +1,7 @@
 package day03
 
 import (
+	_ "embed"
 	"fmt"
 	"strconv"
 	"unicode"
@@ -9,6 +10,91 @@ import (
 	"github.com/sunilbpandey/advent-of-code/utils/go/strutils"
 )
 
+//go:embed input.txt
+var content string
+
+func overlaps(start, length, index int) bool {
+	for i := index - 1; i <= index+1; i++ {
+		if i >= start && i < start+length {
+			return true
+		}
+	}
+	return false
+}
+
+func startsNumber(s string) bool {
+	return unicode.IsDigit(rune(s[0]))
+}
+
+func isPartNumber(index int, number string, prev map[int]string, curr map[int]string) bool {
+	for start, value := range prev {
+		if !startsNumber(value) && overlaps(index, len(number), start) {
+			return true
+		}
+	}
+	for start, value := range curr {
+		if !startsNumber(value) && overlaps(index, len(number), start) {
+			return true
+		}
+	}
+	return false
+}
+
+func Part1() string {
+	sum := 0
+	prev := make(map[int]string)
+
+	strutils.ForEachLine(content, func(_ int, line string) {
+		if len(line) == 0 {
+			return
+		}
+
+		curr := make(map[int]string)
+		number := ""
+		for i, c := range line {
+			if unicode.IsDigit(c) {
+				number += string(c)
+			} else {
+				if len(number) > 0 {
+					if isPartNumber(i-len(number), number, prev, curr) {
+						sum += intutils.Atoi(number)
+					} else {
+						curr[i-len(number)] = number
+					}
+					number = ""
+				}
+
+				if c != '.' {
+					for start, value := range prev {
+						if startsNumber(value) && overlaps(start, len(value), i) {
+							sum += intutils.Atoi(value)
+							delete(prev, start)
+						}
+					}
+
+					for start, value := range curr {
+						if startsNumber(value) && overlaps(start, len(value), i) {
+							sum += intutils.Atoi(value)
+							delete(curr, start)
+						}
+					}
+					curr[i] = string(c)
+				}
+			}
+		}
+		if len(number) > 0 {
+			if isPartNumber(len(line)-len(number), number, prev, curr) {
+				sum += intutils.Atoi(number)
+			} else {
+				curr[len(line)-len(number)] = number
+			}
+		}
+
+		prev = curr
+	})
+	return strconv.Itoa(sum)
+}
+
 func findOverlappingGears(linenum, index int, number string, prev map[int]string, curr map[int]string) []string {
 	gears := []string{}
 	for start, value := range prev {

2023/day04/part1.go → 2023/day04/day04.go

@@ -57,3 +57,37 @@ func Part1() string {
 	})
 	return strconv.Itoa(sum)
 }
+
+func Part2() string {
+	total := 0
+	cardsWon := []int{}
+	strutils.ForEachLine(content, func(_ int, line string) {
+		if len(line) == 0 {
+			return
+		}
+
+		copies := 1
+		if len(cardsWon) > 0 {
+			copies += cardsWon[0]
+			cardsWon = cardsWon[1:]
+		}
+
+		lineParts := strings.Split(line, ": ")
+
+		numberParts := strings.Split(lineParts[1], " | ")
+		winningNumbers := parseWinningNumbers(numberParts[0])
+		count := countNumbersWon(winningNumbers, numberParts[1])
+
+		for i := 0; i < len(cardsWon) && count > 0; i++ {
+			cardsWon[i] += copies
+			count--
+		}
+
+		for i := 0; i < count; i++ {
+			cardsWon = append(cardsWon, copies)
+		}
+
+		total += copies
+	})
+	return strconv.Itoa(total)
+}