2022 Day 15, part 1 complete

Going home from C&C

2022/day15/main.go

@@ -0,0 +1,127 @@
+package main
+
+import (
+	"fmt"
+	"math"
+	"os"
+	"strings"
+
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
+
+var part = -1
+var testRow = 2000000
+var watch bool
+var watchRows = 1
+
+func main() {
+	inp := h.StdinToStringSlice()
+	if len(os.Args) > 1 {
+		for _, arg := range os.Args[1:] {
+			if strings.HasPrefix(arg, "--part") || strings.HasPrefix(arg, "-p") {
+				if strings.Contains(arg, "=") {
+					pts := strings.Split(arg, "=")
+					part = h.Atoi(pts[1])
+				}
+			} else if strings.HasPrefix(arg, "--row") || strings.HasPrefix(arg, "-r") {
+				if strings.Contains(arg, "=") {
+					pts := strings.Split(arg, "=")
+					testRow = h.Atoi(pts[1])
+				}
+			} else if strings.HasPrefix(arg, "--watch") || strings.HasPrefix(arg, "-w") {
+				watch = true
+				if strings.Contains(arg, "=") {
+					pts := strings.Split(arg, "=")
+					if pts[1] == "full" {
+						watchRows = -1
+					} else {
+						watchRows = h.Atoi(pts[1])
+					}
+				}
+			}
+		}
+	}
+
+	part1(inp)
+	part2(inp)
+}
+
+func part1(inp []string) {
+	min_x, max_x := math.MaxInt, math.MinInt
+	var spots [][]int
+	for i := range inp {
+		s, b := strToCoords(inp[i])
+		xs, ys, xb, yb := s.X, s.Y, b.X, b.Y
+		dist := s.Distance(b)
+		l, r := xs-dist, xs+dist
+		min_x = h.Min(min_x, l)
+		max_x = h.Max(max_x, r)
+		spots = append(spots, []int{xs, ys, xb, yb, dist})
+	}
+	var nopeCount int
+	for x := min_x; x <= max_x; x++ {
+		for _, c := range spots {
+			if x == c[2] && testRow == c[3] {
+				break
+			}
+			if h.ManhattanDistance(x, testRow, c[0], c[1]) <= c[4] {
+				nopeCount++
+				break
+			}
+		}
+	}
+	fmt.Println("# Part 1")
+	fmt.Println(nopeCount)
+}
+
+func part2(inp []string) {
+	min_x, max_x := math.MaxInt, math.MinInt
+	var spots [][]int
+	for i := range inp {
+		s, b := strToCoords(inp[i])
+		xs, ys, xb, yb := s.X, s.Y, b.X, b.Y
+		dist := s.Distance(b)
+		l, r := xs-dist, xs+dist
+		min_x = h.Min(min_x, l)
+		max_x = h.Max(max_x, r)
+		spots = append(spots, []int{xs, ys, xb, yb, dist})
+	}
+
+	max := testRow * 2
+	var found h.Coordinate
+SEARCH:
+	for y := 0; y <= max; y++ {
+		for x := 0; x <= max; x++ {
+			fmt.Printf("Testing %d,%d...", x, y)
+			var nope bool
+			for _, c := range spots {
+				if x == c[2] && y == c[3] {
+					break
+				}
+				if h.ManhattanDistance(x, y, c[0], c[1]) <= c[4] {
+					nope = true
+					break
+				}
+			}
+			if !nope {
+				fmt.Println("Yup")
+				found = h.Coordinate{X: x, Y: y}
+				break SEARCH
+			}
+			fmt.Println("Nope")
+		}
+	}
+	fmt.Println("# Part 2")
+	fmt.Println(found)
+	fmt.Println((found.X * 4000000) + found.Y)
+}
+
+func printMap(m [][]int) {
+}
+
+func strToCoords(s string) (h.Coordinate, h.Coordinate) {
+	var sensor, beacon h.Coordinate
+	r := strings.NewReader(s)
+	fmt.Fscanf(r, "Sensor at x=%d, y=%d: closest beacon is at x=%d, y=%d", &sensor.X, &sensor.Y, &beacon.X, &beacon.Y)
+	return sensor, beacon
+}