AdventOfCode2019/02/main.go
2021-12-10 17:26:47 -05:00

106 lines
2.1 KiB
Go

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)
}
}
}
}