add day 1 and 2 solutions

day02/cmd/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"fmt"
+	"intcode/internal/interpreter"
+	"intcode/internal/parser"
+)
+
+func main() {
+	sourceProgram, err := parser.ParseFile(nil)
+
+	if err != nil {
+		panic(err)
+	}
+
+	runProgram := make([]int, len(sourceProgram))
+
+	for x := 0; x < 100; x++ {
+		for y := 0; y < 100; y++ {
+			copy(runProgram, sourceProgram)
+
+            runProgram[1], runProgram[2] = x, y
+
+			interpreter := interpreter.Init(runProgram)
+
+			for !interpreter.Next() {}
+
+            if x == 12 && y == 2 {
+                fmt.Printf("Part 1: %v\n", runProgram[0])
+            }
+			if runProgram[0] == 19690720 {
+                fmt.Printf("Part 2: %02d%02d\n", x, y)
+			}
+		}
+	}
+}

day02/go.mod

@@ -0,0 +1,3 @@
+module intcode
+
+go 1.22.4

day02/internal/debugger/debugger.go

@@ -0,0 +1 @@
+package debugger

day02/internal/interpreter/interpreter.go

@@ -0,0 +1,61 @@
+package interpreter
+
+import "fmt"
+
+type Interpreter struct {
+	program            []int
+	instructionPointer int
+}
+
+func Init(program []int) *Interpreter {
+    return &Interpreter {
+        program: program,
+        instructionPointer: 0,
+    }
+}
+
+func (i *Interpreter) Next() bool {
+	opcode := i.getValueAtIndex(i.instructionPointer)
+	ipIncrement := 1
+
+	switch opcode {
+	case 1:
+        i.add()
+        ipIncrement = 4
+	case 2:
+        i.mul()
+        ipIncrement = 4
+	case 99:
+		return true
+	default:
+		panic(fmt.Sprintf("unhandled opcode %v at IP %v", opcode, i.instructionPointer))
+	}
+
+	i.instructionPointer += ipIncrement
+
+	return false
+}
+
+func (i *Interpreter) getValueAtIndex(index int) int {
+    return i.program[index]
+}
+
+func (i *Interpreter) setValueAtIndex(index, value int) {
+    i.program[index] = value
+}
+
+func (i *Interpreter) add() {
+    resIndex := i.getValueAtIndex(i.instructionPointer + 3)
+    arg1Index := i.getValueAtIndex(i.instructionPointer + 1)
+    arg2Index := i.getValueAtIndex(i.instructionPointer + 2)
+
+    i.setValueAtIndex(resIndex, i.getValueAtIndex(arg1Index) + i.getValueAtIndex(arg2Index))
+}
+
+func (i *Interpreter) mul() {
+    resIndex := i.getValueAtIndex(i.instructionPointer + 3)
+    arg1Index := i.getValueAtIndex(i.instructionPointer + 1)
+    arg2Index := i.getValueAtIndex(i.instructionPointer + 2)
+
+    i.setValueAtIndex(resIndex, i.getValueAtIndex(arg1Index) * i.getValueAtIndex(arg2Index))
+}

day02/internal/interpreter/interpreter_test.go

@@ -0,0 +1 @@
+package interpreter

day02/internal/parser/parser.go

@@ -0,0 +1,48 @@
+package parser
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const DefaultFile = "input"
+
+func ParseFile(input *string) ([]int, error) {
+	if input == nil {
+
+		file := DefaultFile
+
+		if len(os.Args) == 2 {
+			file = os.Args[1]
+		}
+
+		inputFile, err := os.Open(file)
+		if err != nil {
+			return nil, fmt.Errorf("could not parse input file: %v", err)
+		}
+
+		fileData, err := io.ReadAll(inputFile)
+		if err != nil {
+			return nil, fmt.Errorf("could not read input file: %v", err)
+		}
+
+		fileStr := strings.TrimSpace(string(fileData))
+		input = &fileStr
+	}
+
+	strNums := strings.Split(*input, ",")
+	opcodes := make([]int, len(strNums))
+
+	for i, v := range strNums {
+		num, err := strconv.Atoi(v)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "WARNING: error parsing int from input, substring was %v", v)
+		}
+		opcodes[i] = num
+	}
+
+	return opcodes, nil
+}