2019/days/19.go

package days

import (
	"fmt"

	u "parnic.com/aoc2019/utilities"
)

type Day19 struct {
	program u.IntcodeProgram
}

func (d *Day19) Parse() {
	d.program = u.LoadIntcodeProgram("19p")
}

func (d Day19) Num() int {
	return 19
}

func (d *Day19) Part1() string {
	grid := make([][]bool, 50)
	for y := 0; y < len(grid); y++ {
		grid[y] = make([]bool, 50)
	}

	count := int64(0)

	for y := 0; y < 50; y++ {
		for x := 0; x < 50; x++ {
			d.program.Reset()
			d.program.RunIn(func(inputStep int) int64 {
				if inputStep == 1 {
					return int64(x)
				}

				return int64(y)
			}, func(val int64, state u.IntcodeProgramState) {
				res := val == 1
				grid[y][x] = res
				if res {
					count++
				}
			})
		}
	}

	// fmt.Println("50x50 tractor view:")
	// for y := 0; y < len(grid); y++ {
	// 	for x := 0; x < len(grid[y]); x++ {
	// 		if grid[y][x] {
	// 			fmt.Print("█")
	// 		} else {
	// 			fmt.Print(" ")
	// 		}
	// 	}
	// 	fmt.Println()
	// }

	return fmt.Sprintf("Points affected in 50x50 area: %s%d%s", u.TextBold, count, u.TextReset)
}

func (d *Day19) Part2() string {
	grid := make([][]bool, 5000)
	for y := 0; y < len(grid); y++ {
		grid[y] = make([]bool, 5000)
	}

	// find first hit
	firstY := 0
	for y := 1; firstY == 0; y++ {
		for x := 0; x < 10*y; x++ {
			d.program.Reset()
			d.program.RunIn(func(inputStep int) int64 {
				if inputStep == 1 {
					return int64(x)
				}
				return int64(y)
			}, func(val int64, state u.IntcodeProgramState) {
				if val == 1 {
					if firstY == 0 {
						firstY = y
						d.program.Stop()
					}
				}
			})
		}
	}

	done := false
	y := firstY
	x := 0
	firstFoundX := 0
	firstFoundY := 0
	lastX := 0
	lastY := 0
	for y = firstY; !done; y++ {
		lastFoundX := -1
		for x = firstFoundX; lastFoundX == -1 || lastFoundX == x-1; x++ {
			d.program.Reset()
			d.program.RunIn(func(inputStep int) int64 {
				if inputStep == 1 {
					return int64(x)
				}

				return int64(y)
			}, func(val int64, state u.IntcodeProgramState) {
				res := val == 1
				grid[y][x] = res
				if res {
					if lastFoundX == -1 {
						firstFoundX = x
					}
					lastFoundX = x
				}
			})
		}

		if lastFoundX-firstFoundX+1 >= 100 {
			if firstFoundY == 0 {
				firstFoundY = y
			}
			done = grid[y-100][firstFoundX+100]
			if done {
				for checkY := y - 100; checkY <= y; checkY++ {
					if !grid[checkY][firstFoundX+100] || !grid[checkY][firstFoundX] {
						done = false
						break
					}
				}

				if done {
					lastX = firstFoundX + 100
					lastY = y
				}
			}
		}

		// if lastFoundX-firstFoundX+1 >= 100 {
		// 	fmt.Printf("At y=%d, x reached %d for %d in a row\n", y, lastFoundX, lastFoundX-firstFoundX+1)
		// }
	}

	for y := firstFoundY; y <= lastY; y++ {
		for x = 0; ; x++ {
			if grid[y][x] {
				break
			}
		}

		found := true
		for y2 := y + 1; y2 < y+100; y2++ {
			if !grid[y2][x] {
				found = false
				break
			}
		}

		if found {
			fmt.Printf("100 down, 100 across starts at y=%d, x=%d\n", y, x)
		}
	}

	// fmt.Println("part 2 tractor view:")
	// for y := 0; y < len(grid); y++ {
	// 	for x := 0; x < len(grid[y]); x++ {
	// 		if grid[y][x] {
	// 			fmt.Print("█")
	// 		} else {
	// 			fmt.Print(" ")
	// 		}
	// 	}
	// 	fmt.Println()
	// }

	origX := lastX - 100
	origY := lastY - 100
	result := (origX * 10000) + origY
	return fmt.Sprintf("x=%d, y=%d, orig x=%d, orig y=%d, %s%d%s", lastX, lastY, origX, origY, u.TextBold, result, u.TextReset)
}