add 2021

2021/02/first.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+	"strconv"
+)
+
+var vertical int = 0
+var horizontal int = 0
+func checkErr(e error){
+	if e != nil{
+		log.Fatal(e)
+		panic(e)
+	}
+}
+func main(){
+	f, err:=os.Open("input")
+	checkErr(err)
+	defer f.Close()
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan(){
+		evalCommand(scanner.Text())
+	}
+
+	fmt.Println(horizontal*vertical)
+
+}
+func evalCommand(c string){
+	s := strings.Split(c," ")
+
+	switch s[0]{
+	case "forward":
+		s,err :=	strconv.Atoi(s[1])
+		checkErr(err)
+		horizontal = horizontal+s
+	case "backward":
+		s,err :=	strconv.Atoi(s[1])
+		checkErr(err)
+		horizontal = horizontal-s
+	case "up":
+		s,err :=	strconv.Atoi(s[1])
+		checkErr(err)
+		vertical=vertical-s
+	case "down":
+		s,err :=	strconv.Atoi(s[1])
+		checkErr(err)
+		vertical=vertical+s
+	}
+}

2021/02/second.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+	"strconv"
+)
+
+var vertical int = 0
+var horizontal int = 0
+var aim int = 0
+
+func checkErr(e error){
+	if e != nil{
+		panic(e)
+	}
+}
+func main(){
+	f,e:=os.Open("input")
+	checkErr(e)
+	defer f.Close()
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan(){
+		evalCommand(scanner.Text())
+	}
+	defer fmt.Println(horizontal*vertical)
+}
+func evalCommand(c string){
+	s := strings.Split(c," ")
+	value,e:=	strconv.Atoi(s[1])
+	checkErr(e)
+	switch s[0]{
+	case "forward":
+		horizontal += value
+		vertical += aim* value
+	case "up":
+		aim -= value
+	case "down":
+		aim += value
+	}
+}

2021/02/testinput

@@ -0,0 +1,6 @@
+forward 5
+down 5
+forward 8
+up 3
+down 8
+forward 2