feat: solutions for day 25

Author: nikolay

25/input.txt

@@ -0,0 +1,117 @@
+11-00
+2--2==212=12
+1=0110121=2
+1=012-21-=121
+1==0-1121-=200=2212
+1=1210===00=
+11210021-0001010-
+12=1-10-1-
+212-2==221-210-21
+1=-01=0-02-2-=-222=
+1=022000===-22010
+1=01=12202
+11=
+202-1
+2-12-2=--1
+10-=-00=101=-0-=-0
+1112-1
+2--1201
+1=1==-020=1-
+1--0-=2-0022-
+1=-1-21-200-102=
+11=100021210
+1=2=01=2-=01-=
+1=0120-11-0-=-2=-2
+1=-20221=2=-2=
+1-0
+1=00=-=11100--=2
+22122
+1=102222
+1210=1=001-=000
+1--200102022-=
+102=12=-1==
+100=
+20-02
+10
+10==-102
+11=020-0210-1-2012=
+12-11=0-1-=
+20=-
+212=1-1-10
+1=20=1-=2-11=0
+1=22
+120=2202=12200
+1-0-1
+211011-11=
+2=120=--==0==--0-0
+110-0-=-10-1-112
+1=2=1-=1-2
+1=12==10
+10=2110
+22222-1=01-1
+111-=2=22-==-00
+10===2-2=21100-1=
+100-21-0-1=021
+2-21=0
+1===002012=2=-1121
+122222-101=1-==2-2=
+112=0
+2--212=0
+110--2-0022--01=-
+1-0-0=0-1011-2-=0--2
+1=--0-2=1
+2=
+1=1
+1022=1--2---120
+2-1=2-22--21=1-212
+22=-11-0=-1
+2==210022=
+11=000=002-2002-1=
+2-2=02=0
+1=00-=----=
+1=121-2
+12-2=2-=2=2022
+2=110=1=2=02
+2
+1=0--02-121
+1200-2000=0
+1==--021--2=-
+12-1=22=-02--2-
+1=1=1--121-1221
+2-0212=
+21-==0-201-
+20212=1
+111--
+22-2=-1
+112
+2=2-==101
+1-=1
+12211=010=-=10--
+2211
+21-110-1-22==-10
+121-1-
+22000=-=2-0=012
+212-02
+102
+2-110=11=--
+11=11===0
+1=210-0120
+1=--1011
+2=00022==21-1=-2
+21=1-==2---2=0-2
+1220-11=022122
+21210=01
+1==1-2
+2=2
+11-11122=-
+200-0=21202-=
+2=-11
+2==2=0=1120221
+101010
+1=2=-=--=-2-0=
+111=0=--
+1=0121-=2
+1==1=1
+2-0222=2=-
+12=
+10-=0-2

25/main.go

@@ -0,0 +1,86 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+)
+
+type Coord struct {
+	x, y int
+}
+
+var Zero = Coord{}
+
+func (coord Coord) Move(dir int) Coord {
+	return coord.Add([]Coord{{1, 0}, {0, 1}, {-1, 0}, {0, -1}}[dir])
+}
+
+func (coord Coord) Add(add Coord) Coord {
+	return Coord{coord.x + add.x, coord.y + add.y}
+}
+
+func SnafuToDecimal(snafu string) int {
+	decimal := 0
+	for _, ch := range snafu {
+		var digit int
+		switch ch {
+		case '=':
+			digit = -2
+		case '-':
+			digit = -1
+		default:
+			digit = int(ch - '0')
+		}
+		decimal *= 5
+		decimal += digit
+	}
+	return decimal
+}
+
+func DecimalToSnafu(decimal int) string {
+	switch decimal {
+	case -2:
+		return "="
+	case -1:
+		return "-"
+	case 0:
+		return "0"
+	}
+	snafu := ""
+	for decimal > 0 {
+		digit := decimal % 5
+		if digit > 2 {
+			decimal += 5
+		}
+		snafu = []string{"0", "1", "2", "=", "-"}[digit] + snafu
+		decimal = decimal / 5
+	}
+	return snafu
+}
+
+func main() {
+	file, err := os.Open("input.txt")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer file.Close()
+
+	sum := 0
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if len(line) == 0 {
+			continue
+		}
+		sum += SnafuToDecimal(line)
+	}
+	if err := scanner.Err(); err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Println(DecimalToSnafu(sum))
+}

25/sample.txt

@@ -0,0 +1,13 @@
+1=-0-2
+12111
+2=0=
+21
+2=01
+111
+20012
+112
+1=-1=
+1-12
+12
+1=
+122