mirror of
https://github.com/Threnklyn/advent-of-code-go.git
synced 2026-05-18 19:13:27 +02:00
alexchao26
280 lines
8.7 KiB
Go
280 lines
8.7 KiB
Go
/*
|
|
Intcode struct is defined within this file
|
|
Robot struct houses an Intcode computer and a method to initialize the floor details
|
|
- an algorithm in the main function traverses all tiles and checks all of its neighbors
|
|
- for all intersections that are found, their alignment parameters are calculated & added to a sum
|
|
*/
|
|
|
|
package main
|
|
|
|
import (
|
|
"adventofcode/util"
|
|
"fmt"
|
|
"log"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
func main() {
|
|
// read the input file, modify it to a slice of numbers
|
|
inputFile := util.ReadFile("../input.txt")
|
|
|
|
splitStrings := strings.Split(inputFile, ",")
|
|
|
|
inputNumbers := make([]int, len(splitStrings))
|
|
for i, v := range splitStrings {
|
|
inputNumbers[i], _ = strconv.Atoi(v)
|
|
}
|
|
|
|
robot := MakeRobot(inputNumbers)
|
|
|
|
// fire off function to populate the robot's floorGrid property
|
|
robot.GetFloorGrid()
|
|
|
|
// find all intersections and sum up the products of its row and col - 0-indexed
|
|
// helper directions to traverse in all 4 directions
|
|
dRow := []int{0, 0, -1, 1}
|
|
dCol := []int{-1, 1, 0, 0}
|
|
|
|
var sumOfAlignmentParameters int
|
|
for row, rowSlice := range robot.floorGrid {
|
|
for col, floorType := range rowSlice {
|
|
// traverse to the four directions around the particular cell, increment surroundingScaffolds
|
|
// by 1 for every neighbor that is a scaffold,
|
|
// if this is equal to 4 after looping, then an intersection was found
|
|
var surroundingScaffolds int
|
|
for i := 0; i < 4; i++ {
|
|
neighborRow, neighborCol := row+dRow[i], col+dCol[i]
|
|
isInbounds := neighborRow >= 0 && neighborRow < len(robot.floorGrid) && neighborCol >= 0 && neighborCol < len(robot.floorGrid[0])
|
|
if isInbounds && floorType == "#" && robot.floorGrid[neighborRow][neighborCol] == "#" {
|
|
surroundingScaffolds++
|
|
}
|
|
}
|
|
|
|
if surroundingScaffolds == 4 {
|
|
sumOfAlignmentParameters += row * col
|
|
}
|
|
}
|
|
}
|
|
|
|
fmt.Println("Sum of alignment parameters: ", sumOfAlignmentParameters)
|
|
}
|
|
|
|
// Robot struct to maintain detail's on the Robot's coordinates, path
|
|
type Robot struct {
|
|
row, col int
|
|
floorGrid [][]string
|
|
computer *Intcode
|
|
}
|
|
|
|
// MakeRobot returns an instance of a Robot
|
|
func MakeRobot(intcodeInput []int) *Robot {
|
|
return &Robot{
|
|
computer: MakeComputer(intcodeInput),
|
|
}
|
|
}
|
|
|
|
// GetFloorGrid will fire off the computer and populate the robot's floor details
|
|
func (robot *Robot) GetFloorGrid() {
|
|
robot.computer.Step(-1)
|
|
robot.floorGrid = append(robot.floorGrid, []string{})
|
|
row := 0
|
|
|
|
for _, v := range robot.computer.Outputs {
|
|
switch v {
|
|
case 10:
|
|
row++
|
|
robot.floorGrid = append(robot.floorGrid, []string{})
|
|
default:
|
|
tileType := string(v)
|
|
robot.floorGrid[row] = append(robot.floorGrid[row], tileType)
|
|
}
|
|
}
|
|
|
|
// parse off empty slices @ end
|
|
for i := len(robot.floorGrid) - 1; i >= 0; i-- {
|
|
if len(robot.floorGrid[i]) == 0 {
|
|
robot.floorGrid = robot.floorGrid[:len(robot.floorGrid)-1]
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
Intcode is an OOP approach *************************************************
|
|
MakeComputer is equivalent to the constructor
|
|
Step takes in an input int and updates properties in the computer:
|
|
- InstructionIndex: where to read the next instruction from
|
|
- LastOutput, what the last opcode 4 outputted
|
|
- PuzzleIndex based if the last instruction modified the puzzle at all
|
|
****************************************************************************/
|
|
type Intcode struct {
|
|
PuzzleInput []int // file/puzzle input parsed into slice of ints
|
|
InstructionIndex int // stores the index where the next instruction is
|
|
RelativeBase int // relative base for opcode 9 and param mode 2
|
|
Outputs []int // stores all outputs
|
|
IsRunning bool // will be true until a 99 opcode is hit
|
|
}
|
|
|
|
// MakeComputer initializes a new comp
|
|
func MakeComputer(PuzzleInput []int) *Intcode {
|
|
puzzleInputCopy := make([]int, len(PuzzleInput))
|
|
copy(puzzleInputCopy, PuzzleInput)
|
|
|
|
comp := Intcode{
|
|
puzzleInputCopy,
|
|
0,
|
|
0,
|
|
make([]int, 0),
|
|
true,
|
|
}
|
|
return &comp
|
|
}
|
|
|
|
// Step will read the next 4 values in the input `sli` and make updates
|
|
// according to the opcodes
|
|
func (comp *Intcode) Step(input int) {
|
|
// read the instruction, opcode and the indexes where the params point to
|
|
opcode, paramIndexes := comp.GetOpCodeAndParamIndexes()
|
|
param1, param2, param3 := paramIndexes[0], paramIndexes[1], paramIndexes[2]
|
|
|
|
// ensure params are within the bounds of PuzzleInput, resize if necessary
|
|
switch opcode {
|
|
case 1, 2, 7, 8:
|
|
comp.ResizeMemory(param1, param2, param3)
|
|
case 5, 6:
|
|
comp.ResizeMemory(param1, param2)
|
|
case 3, 4, 9:
|
|
comp.ResizeMemory(param1)
|
|
}
|
|
|
|
switch opcode {
|
|
case 99: // 99: Terminates program
|
|
fmt.Println("Terminating...")
|
|
comp.IsRunning = false
|
|
case 1: // 1: Add next two paramIndexes, store in third
|
|
comp.PuzzleInput[param3] = comp.PuzzleInput[param1] + comp.PuzzleInput[param2]
|
|
comp.InstructionIndex += 4
|
|
comp.Step(input)
|
|
case 2: // 2: Multiply next two and store in third
|
|
comp.PuzzleInput[param3] = comp.PuzzleInput[param1] * comp.PuzzleInput[param2]
|
|
comp.InstructionIndex += 4
|
|
comp.Step(input)
|
|
case 3: // 3: Takes one input and saves it to position of one parameter
|
|
// check if input has already been used (i.e. input == -1)
|
|
// if it's been used, return out to prevent further Steps
|
|
// NOTE: making a big assumption that -1 will never be an input...
|
|
if input == -1 {
|
|
return
|
|
}
|
|
|
|
// else recurse with a -1 to signal the initial input has been processed
|
|
comp.PuzzleInput[param1] = input
|
|
comp.InstructionIndex += 2
|
|
comp.Step(-1)
|
|
case 4: // 4: outputs its input value
|
|
// set LastOutput of the computer & log it
|
|
comp.Outputs = append(comp.Outputs, comp.PuzzleInput[param1])
|
|
// fmt.Printf("Opcode 4 output: %v\n", comp.LastOutput)
|
|
comp.InstructionIndex += 2
|
|
|
|
// continue running until terminates or asks for another input
|
|
comp.Step(input)
|
|
// 5: jump-if-true: if first param != 0, move pointer to second param, else nothing
|
|
case 5:
|
|
if comp.PuzzleInput[param1] != 0 {
|
|
comp.InstructionIndex = comp.PuzzleInput[param2]
|
|
} else {
|
|
comp.InstructionIndex += 3
|
|
}
|
|
comp.Step(input)
|
|
// 6: jump-if-false, if first param == 0 then set instruction pointer to 2nd param, else nothing
|
|
case 6:
|
|
if comp.PuzzleInput[param1] == 0 {
|
|
comp.InstructionIndex = comp.PuzzleInput[param2]
|
|
} else {
|
|
comp.InstructionIndex += 3
|
|
}
|
|
comp.Step(input)
|
|
// 7: less-than, if param1 < param2 then store 1 in postion of 3rd param, else store 0
|
|
case 7:
|
|
if comp.PuzzleInput[param1] < comp.PuzzleInput[param2] {
|
|
comp.PuzzleInput[param3] = 1
|
|
} else {
|
|
comp.PuzzleInput[param3] = 0
|
|
}
|
|
comp.InstructionIndex += 4
|
|
comp.Step(input)
|
|
// 8: equals, if param1 == param2 then set position of 3rd param to 1, else store 0
|
|
case 8:
|
|
if comp.PuzzleInput[param1] == comp.PuzzleInput[param2] {
|
|
comp.PuzzleInput[param3] = 1
|
|
} else {
|
|
comp.PuzzleInput[param3] = 0
|
|
}
|
|
comp.InstructionIndex += 4
|
|
comp.Step(input)
|
|
// 9: adjust relative base
|
|
case 9:
|
|
comp.RelativeBase += comp.PuzzleInput[param1]
|
|
comp.InstructionIndex += 2
|
|
comp.Step(input)
|
|
default:
|
|
log.Fatalf("Error: unknown opcode %v at index %v", opcode, comp.PuzzleInput[comp.InstructionIndex])
|
|
}
|
|
}
|
|
|
|
/*
|
|
GetOpCodeAndParamIndexes will parse the instruction at comp.PuzzleInput[comp.InstructionIndex]
|
|
- opcode will be the left two digits, mod by 100 will get that
|
|
- rest of instructions will be grabbed via mod 10
|
|
- these also have to be parsed for the
|
|
*/
|
|
func (comp *Intcode) GetOpCodeAndParamIndexes() (int, [3]int) {
|
|
instruction := comp.PuzzleInput[comp.InstructionIndex]
|
|
|
|
// opcode is the lowest two digits, so mod by 100
|
|
opcode := instruction % 100
|
|
instruction /= 100
|
|
|
|
// assign the indexes that need to be read by reading the parameter modes
|
|
var paramIndexes [3]int
|
|
for i := 1; i <= 3 && comp.InstructionIndex+i < len(comp.PuzzleInput); i++ {
|
|
// grab the mode with a mod, last digit
|
|
mode := instruction % 10
|
|
instruction /= 10
|
|
|
|
switch mode {
|
|
case 0: // position mode, index will be the value at the index
|
|
paramIndexes[i-1] = comp.PuzzleInput[comp.InstructionIndex+i]
|
|
case 1: // immediate mode, the index itself
|
|
paramIndexes[i-1] = comp.InstructionIndex + i
|
|
case 2: // relative mode, like position mode but index is added to relative base
|
|
paramIndexes[i-1] = comp.PuzzleInput[comp.InstructionIndex+i] + comp.RelativeBase
|
|
}
|
|
}
|
|
|
|
return opcode, paramIndexes
|
|
}
|
|
|
|
// ResizeMemory will take any number of integers and resize the computer's memory appropriately
|
|
func (comp *Intcode) ResizeMemory(sizes ...int) {
|
|
// get largest of input sizes
|
|
maxArg := sizes[0]
|
|
for _, v := range sizes {
|
|
if v > maxArg {
|
|
maxArg = v
|
|
}
|
|
}
|
|
|
|
// resize if PuzzleInput's length is shorter
|
|
if maxArg >= len(comp.PuzzleInput) {
|
|
// make empty slice to copy into, of the new, larger size
|
|
resizedPuzzleInput := make([]int, maxArg+1)
|
|
// copy old puzzle input values in
|
|
copy(resizedPuzzleInput, comp.PuzzleInput)
|
|
|
|
// overwrite puzzle input
|
|
comp.PuzzleInput = resizedPuzzleInput
|
|
}
|
|
}
|