day 2 part 1 completed

day2p1/input.txt

@@ -0,0 +1 @@
+1,0,0,3,1,1,2,3,1,3,4,3,1,5,0,3,2,13,1,19,1,19,9,23,1,5,23,27,1,27,9,31,1,6,31,35,2,35,9,39,1,39,6,43,2,9,43,47,1,47,6,51,2,51,9,55,1,5,55,59,2,59,6,63,1,9,63,67,1,67,10,71,1,71,13,75,2,13,75,79,1,6,79,83,2,9,83,87,1,87,6,91,2,10,91,95,2,13,95,99,1,9,99,103,1,5,103,107,2,9,107,111,1,111,5,115,1,115,5,119,1,10,119,123,1,13,123,127,1,2,127,131,1,131,13,0,99,2,14,0,0

day2p1/main.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// nolint
+var (
+	in  io.Reader = os.Stdin
+	out io.Writer = os.Stdout
+)
+
+func main() {
+	prog := ""
+
+	fmt.Fscanf(in, "%s", &prog)
+
+	strs := strings.Split(prog, ",")
+	opcodes := make([]int, len(strs))
+
+	for i, s := range strs {
+		res, _ := strconv.Atoi(s)
+		opcodes[i] = res
+	}
+
+	opcodes[1] = 12
+	opcodes[2] = 2
+
+	for pc := 0; opcodes[pc] != 99; pc += 4 {
+		val1 := opcodes[opcodes[pc+1]]
+		val2 := opcodes[opcodes[pc+2]]
+		outPos := opcodes[pc+3]
+
+		switch code := opcodes[pc]; code {
+		case 1:
+			opcodes[outPos] = val1 + val2
+		case 2:
+			opcodes[outPos] = val1 * val2
+		}
+	}
+
+	fmt.Fprintln(out, opcodes[0])
+}

day2p1/main_test.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"bytes"
+	"os"
+	"strings"
+	"testing"
+)
+
+func TestMain(t *testing.T) {
+	file, _ := os.Open("input.txt")
+	in = file
+	buff := new(bytes.Buffer)
+	out = buff
+
+	main()
+
+	result := strings.TrimSpace(buff.String())
+	if expected := "3409710"; expected != result {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+
+	file.Close()
+}
+
+func BenchmarkMain(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		file, _ := os.Open("input.txt")
+		in = file
+		buff := new(bytes.Buffer)
+		out = buff
+
+		main()
+		file.Close()
+	}
+}