Day 2 initial solution

There's room to optimize part 2, but I wanted to commit my original brute-force solution first.

days/02.go

@@ -0,0 +1,70 @@
+package days
+
+import (
+	"fmt"
+
+	"parnic.com/aoc2019/utilities"
+)
+
+type Day02 struct {
+	program []int64
+}
+
+func (d *Day02) Parse() {
+	d.program = utilities.ParseIntcodeProgram(utilities.GetStringContents("02p"))
+}
+
+func (d Day02) Num() int {
+	return 2
+}
+
+func (d *Day02) getProgramWithParams(param1, param2 int64) []int64 {
+	program := make([]int64, len(d.program))
+	copy(program, d.program)
+	program[1] = param1
+	program[2] = param2
+	return program
+}
+
+func (d *Day02) Part1() string {
+	program := d.getProgramWithParams(12, 2)
+	utilities.RunIntcodeProgram(program)
+
+	return fmt.Sprintf("Position 0 = %s%d%s", utilities.TextBold, program[0], utilities.TextReset)
+}
+
+func (d *Day02) Part2() string {
+	sentinel := int64(19690720)
+
+	var noun int64
+	var verb int64
+	found := false
+	for noun = 0; noun <= 99; noun++ {
+		for verb = 0; verb <= 99; verb++ {
+			program := d.getProgramWithParams(noun, verb)
+			utilities.RunIntcodeProgram(program)
+
+			if program[0] == sentinel {
+				found = true
+				break
+			}
+		}
+
+		if found {
+			break
+		}
+	}
+
+	if !found {
+		panic("!found")
+	}
+
+	return fmt.Sprintf("%d created by noun=%d, verb=%d. 100 * noun + verb = %s%d%s",
+		sentinel,
+		noun,
+		verb,
+		utilities.TextBold,
+		100*noun+verb,
+		utilities.TextReset,
+	)
+}

inputs/02p.txt

@@ -0,0 +1 @@
+1,0,0,3,1,1,2,3,1,3,4,3,1,5,0,3,2,10,1,19,1,19,9,23,1,23,6,27,1,9,27,31,1,31,10,35,2,13,35,39,1,39,10,43,1,43,9,47,1,47,13,51,1,51,13,55,2,55,6,59,1,59,5,63,2,10,63,67,1,67,9,71,1,71,13,75,1,6,75,79,1,10,79,83,2,9,83,87,1,87,5,91,2,91,9,95,1,6,95,99,1,99,5,103,2,103,10,107,1,107,6,111,2,9,111,115,2,9,115,119,2,13,119,123,1,123,9,127,1,5,127,131,1,131,2,135,1,135,6,0,99,2,0,14,0

main.go

@@ -26,6 +26,7 @@ const (
 
 var dayMap = map[int]day{
 	1: &days.Day01{},
+	2: &days.Day02{},
 }
 
 func main() {

utilities/intcode.go

@@ -0,0 +1,47 @@
+package utilities
+
+import (
+	"strconv"
+	"strings"
+)
+
+func ParseIntcodeProgram(programStr string) []int64 {
+	nums := strings.Split(programStr, ",")
+	program := make([]int64, len(nums))
+	for idx, num := range nums {
+		iNum, err := strconv.ParseInt(num, 10, 64)
+		if err != nil {
+			panic(err)
+		}
+		program[idx] = iNum
+	}
+
+	return program
+}
+
+func RunIntcodeProgram(program []int64) {
+	for instructionPointer := 0; instructionPointer < len(program); {
+		opcode := program[instructionPointer]
+		switch opcode {
+		case 1:
+			param1 := program[instructionPointer+1]
+			param2 := program[instructionPointer+2]
+			param3 := program[instructionPointer+3]
+			program[param3] = program[param1] + program[param2]
+
+			instructionPointer += 4
+			break
+		case 2:
+			param1 := program[instructionPointer+1]
+			param2 := program[instructionPointer+2]
+			param3 := program[instructionPointer+3]
+			program[param3] = program[param1] * program[param2]
+
+			instructionPointer += 4
+			break
+		case 99:
+			instructionPointer = len(program)
+			break
+		}
+	}
+}

utilities/parsing.go

@@ -24,6 +24,17 @@ func getData(filename string, lineHandler func(line string)) {
 	}
 }
 
+func GetStringContents(filename string) string {
+	var retval string
+	getData(filename, func(line string) {
+		if len(retval) != 0 {
+			panic("tried to parse multi-line file as a single line")
+		}
+		retval = line
+	})
+	return retval
+}
+
 func GetStringLines(filename string) []string {
 	retval := make([]string, 0)
 	getData(filename, func(line string) {