DaySix.go

package adventofcode2015

import (
	"fmt"
	"strconv"
	"strings"
)

func setPixel(grid [][]bool, x, y int, state bool) {
	grid[y][x] = state
}

func togglePixel(grid [][]bool, x, y int) {
	grid[y][x] = !grid[y][x]
}

func turnPixelOn(grid [][]bool, x, y int) {
	setPixel(grid, x, y, true)
}

func turnPixelOff(grid [][]bool, x, y int) {
	setPixel(grid, x, y, false)
}

func superBrightenPixel(grid [][]int, x, y int) {
	grid[y][x] = grid[y][x] + 2
}

func brightenPixel(grid [][]int, x, y int) {
	grid[y][x] = grid[y][x] + 1
}
func dimPixel(grid [][]int, x, y int) {
	if grid[y][x] > 0 {
		grid[y][x] = grid[y][x] - 1
	}
}

func countPixelBrightness(grid [][]int) int {
	count := 0

	for i := 0; i < len(grid); i++ {
		for j := 0; j < len(grid[i]); j++ {
			count += grid[i][j]
		}
	}

	return count
}

func countLitPixels(grid [][]bool) int {
	count := 0

	for i := 0; i < len(grid); i++ {
		for j := 0; j < len(grid[i]); j++ {

			if grid[i][j] {
				count++
			}
		}
	}

	return count
}

func showGrid(grid [][]bool) {

	for i := 0; i < len(grid); i++ {
		for j := 0; j < len(grid[i]); j++ {

			if grid[i][j] {
				fmt.Print("#")
			} else {
				fmt.Print(" ")
			}
		}

		fmt.Print("\n")
	}
}

func parsePoints(command string) (minX, minY, maxX, maxY int) {

	parts := strings.Split(command, " ")
	topLeft := strings.Split(parts[0], ",")
	bottomRight := strings.Split(parts[2], ",")

	minX, _ = strconv.Atoi(topLeft[0])
	minY, _ = strconv.Atoi(topLeft[1])
	maxX, _ = strconv.Atoi(bottomRight[0])
	maxY, _ = strconv.Atoi(bottomRight[1])

	return minX, minY, maxX, maxY
}

func DaySixPartOne() {

	const gridWidth = 1000
	const gridHeight = 1000

	fmt.Println("Day Six")

	fmt.Println("Grid Width: ", gridWidth)
	fmt.Println("Grid Height: ", gridHeight)

	var grid [][]bool

	grid = make([][]bool, gridHeight)

	for i := 0; i < gridHeight; i++ {
		grid[i] = make([]bool, gridWidth)
	}

	input := ReadFile("day6-input.txt")

	steps := strings.Split(input, "\n")

	for i := 0; i < len(steps); i++ {

		step := steps[i]

		//fmt.Println(step)

		if strings.HasPrefix(step, "toggle") {
			toggle := step[len("toggle "):]
			minX, minY, maxX, maxY := parsePoints(toggle)
			for y := minY; y <= maxY; y++ {
				for x := minX; x <= maxX; x++ {
					togglePixel(grid, x, y)
				}
			}
		}

		if strings.HasPrefix(step, "turn on") {
			toggle := step[len("turn on "):]
			minX, minY, maxX, maxY := parsePoints(toggle)
			for y := minY; y <= maxY; y++ {
				for x := minX; x <= maxX; x++ {
					turnPixelOn(grid, x, y)
				}
			}
		}

		if strings.HasPrefix(step, "turn off") {
			toggle := step[len("turn off "):]
			minX, minY, maxX, maxY := parsePoints(toggle)
			for y := minY; y <= maxY; y++ {
				for x := minX; x <= maxX; x++ {
					turnPixelOff(grid, x, y)
				}
			}
		}
	}

	//showGrid(grid)
	fmt.Println("Lit pixels: ", countLitPixels(grid))
}

func DaySixPartTwo() {

	const gridWidth = 1000
	const gridHeight = 1000

	fmt.Println("Day Six - Part Two")

	fmt.Println("Grid Width: ", gridWidth)
	fmt.Println("Grid Height: ", gridHeight)

	var grid [][]int

	grid = make([][]int, gridHeight)

	for i := 0; i < gridHeight; i++ {
		grid[i] = make([]int, gridWidth)
	}

	input := ReadFile("day6-input.txt")

	steps := strings.Split(input, "\n")

	for i := 0; i < len(steps); i++ {

		step := steps[i]

		//fmt.Println(step)

		if strings.HasPrefix(step, "toggle") {
			toggle := step[len("toggle "):]
			minX, minY, maxX, maxY := parsePoints(toggle)
			for y := minY; y <= maxY; y++ {
				for x := minX; x <= maxX; x++ {
					superBrightenPixel(grid, x, y)
				}
			}
		}

		if strings.HasPrefix(step, "turn on") {
			toggle := step[len("turn on "):]
			minX, minY, maxX, maxY := parsePoints(toggle)
			for y := minY; y <= maxY; y++ {
				for x := minX; x <= maxX; x++ {
					brightenPixel(grid, x, y)
				}
			}
		}

		if strings.HasPrefix(step, "turn off") {
			toggle := step[len("turn off "):]
			minX, minY, maxX, maxY := parsePoints(toggle)
			for y := minY; y <= maxY; y++ {
				for x := minX; x <= maxX; x++ {
					dimPixel(grid, x, y)
				}
			}
		}
	}

	//showGrid(grid)
	fmt.Println("Brightness: ", countPixelBrightness(grid))
}