day 2

01/main.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"time"
+)
+
+func mustAtoi(line string) int {
+	i, _ := strconv.Atoi(line)
+	return i
+}
+
+// I apparently did this but no longer have the code for it.
+
+func main() {
+	start := time.Now()
+	partOne()
+	duration := time.Since(start)
+	partTwo()
+	duration2 := time.Since(start)
+	fmt.Printf("p1: %s, p2: %s\n", duration, duration2-duration)
+}
+
+func makeScanner(test bool) *bufio.Scanner {
+	var f *os.File
+	if test {
+		f, _ = os.Open("inputs/testinput")
+	} else {
+		f, _ = os.Open("inputs/input")
+	}
+	reader := bufio.NewReader(f)
+	return bufio.NewScanner(reader)
+}
+
+func partOne() {
+	scanner := makeScanner(false)
+
+	for scanner.Scan() {
+		// line := scanner.Text()
+	}
+}
+
+func partTwo() {
+	scanner := makeScanner(false)
+
+	for scanner.Scan() {
+		// line := scanner.Text()
+	}
+}

02/main.go

@@ -0,0 +1,105 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"time"
+)
+
+func mustAtoi(line string) int {
+	i, _ := strconv.Atoi(line)
+	return i
+}
+
+func main() {
+	start := time.Now()
+	partOne()
+	duration := time.Since(start)
+	partTwo()
+	duration2 := time.Since(start)
+	fmt.Printf("p1: %s, p2: %s\n", duration, duration2-duration)
+}
+
+func makeScanner(test bool) *bufio.Scanner {
+	var f *os.File
+	if test {
+		f, _ = os.Open("inputs/testinput")
+	} else {
+		f, _ = os.Open("inputs/input")
+	}
+	reader := bufio.NewReader(f)
+	return bufio.NewScanner(reader)
+}
+
+type intCodeProgram struct {
+	program []int
+}
+
+func parseIntCodeInput(line string) intCodeProgram {
+	program := intCodeProgram{
+		program: make([]int, 0),
+	}
+	acc := []byte{}
+	for _, v := range line {
+		switch v {
+		case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			acc = append(acc, byte(v))
+		case ',':
+			program.program = append(program.program, mustAtoi(string(acc)))
+			acc = []byte{}
+		}
+	}
+	program.program = append(program.program, mustAtoi(string(acc)))
+	return program
+}
+
+func runIntCodeProgram(p intCodeProgram) intCodeProgram {
+	pos := 0
+	for {
+		switch p.program[pos] {
+		case 1:
+			sum := p.program[p.program[pos+1]] + p.program[p.program[pos+2]]
+			p.program[p.program[pos+3]] = sum
+			pos += 4
+		case 2:
+			mul := p.program[p.program[pos+1]] * p.program[p.program[pos+2]]
+			p.program[p.program[pos+3]] = mul
+			pos += 4
+		case 99:
+			return p
+		}
+	}
+}
+
+func partOne() {
+	scanner := makeScanner(false)
+
+	scanner.Scan()
+	prog := parseIntCodeInput(scanner.Text())
+	prog.program[1] = 12
+	prog.program[2] = 2
+	fmt.Println(runIntCodeProgram(prog).program[0])
+}
+
+func partTwo() {
+	scanner := makeScanner(false)
+
+	scanner.Scan()
+	prog := parseIntCodeInput(scanner.Text())
+	possibleInputs := len(prog.program)
+	for i := 0; i < possibleInputs; i++ {
+		for j := 0; j < possibleInputs; j++ {
+			thisRun := intCodeProgram{
+				program: make([]int, len(prog.program)),
+			}
+			copy(thisRun.program, prog.program)
+			thisRun.program[1] = i
+			thisRun.program[2] = j
+			if runIntCodeProgram(thisRun).program[0] == 19690720 {
+				fmt.Println(100*i + j)
+			}
+		}
+	}
+}