2022 Day 14 Complete!

2022/day14/main.go

@@ -0,0 +1,180 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
+
+var debug bool
+
+func main() {
+	inp := h.StdinToStringSlice()
+	part1(inp)
+	part2(inp)
+}
+
+func Check(spot h.Coordinate, walls, sand *h.CoordByteMap) byte {
+	if v := walls.Get(spot); v != 0 {
+		return v
+	}
+	return sand.Get(spot)
+}
+
+func part1(inp []string) {
+	m := BuildMap(inp)
+	// Now start dropping sand
+	var err error
+	for err == nil {
+		entry := &h.Coordinate{X: 500, Y: 0}
+		err = Drop(entry, m)
+		if err != nil {
+		} else {
+			m.Put(*entry, 'o')
+		}
+	}
+	fmt.Println("# Part 1")
+	fmt.Println(m.Count('o'), "grains of sand")
+}
+
+// Drop 'grain' into the field described by 'walls', and 'sand'
+// It returns the path that it took
+// If it flows off the map, error is returned
+func Drop(grain *h.Coordinate, m *h.CoordByteMap) error {
+	var path []h.Coordinate
+	prevX, prevY := grain.X, grain.Y
+	for {
+		if grain.South().Y > m.BRY {
+			return errors.New("Overflow")
+		} else if m.Get(grain.South()) == 0 {
+			path = append(path, grain.South())
+			grain.MoveSouth()
+		} else if m.Get(grain.SW()) == 0 {
+			path = append(path, grain.SW())
+			grain.MoveSW()
+		} else if m.Get(grain.SE()) == 0 {
+			path = append(path, grain.SE())
+			grain.MoveSE()
+		}
+		if debug {
+			fmt.Println(h.CLEAR_SCREEN)
+			m.Put(*grain, 'o')
+			fmt.Println(m)
+			m.Delete(*grain)
+			time.Sleep(time.Second / 100)
+		}
+		// Grain didn't move, must be at rest
+		if grain.X == prevX && grain.Y == prevY {
+			return nil
+		}
+		prevX, prevY = grain.X, grain.Y
+	}
+}
+
+func part2(inp []string) {
+	m := BuildMap(inp)
+	m.BRY += 1
+	// Now start dropping sand
+	var err error
+	for err == nil {
+		entry := &h.Coordinate{X: 500, Y: 0}
+		err = Drop2(entry, m)
+		m.Put(*entry, 'o')
+	}
+	fmt.Println("# Part 2")
+	fmt.Println(m.Count('o'), "grains of sand")
+}
+func Drop2(grain *h.Coordinate, m *h.CoordByteMap) error {
+	var path []h.Coordinate
+	prevX, prevY := grain.X, grain.Y
+	var moved bool
+	for {
+		if grain.Y == m.BRY {
+			return nil
+		}
+		if m.Get(grain.South()) == 0 {
+			path = append(path, grain.South())
+			grain.MoveSouth()
+			moved = true
+		} else if m.Get(grain.SW()) == 0 {
+			path = append(path, grain.SW())
+			grain.MoveSW()
+			moved = true
+		} else if m.Get(grain.SE()) == 0 {
+			path = append(path, grain.SE())
+			grain.MoveSE()
+			moved = true
+		}
+		if debug {
+			fmt.Println(h.CLEAR_SCREEN)
+			m.Put(*grain, 'o')
+			fmt.Println(m)
+			m.Delete(*grain)
+			time.Sleep(time.Second / 100)
+		}
+		if grain.X == prevX && grain.Y == prevY {
+			// Grain didn't move, must be at rest
+			if !moved {
+				return errors.New("Full")
+			}
+			return nil
+		}
+		prevX, prevY = grain.X, grain.Y
+	}
+}
+
+func BuildMap(inp []string) *h.CoordByteMap {
+	m := h.NewCoordByteMap()
+	m.TLY = 0
+	m.StringEmptyIsSpace = true
+	m.StringEmptyByte = '.'
+	for i := range inp {
+		var start, end *h.Coordinate
+		pts := strings.Split(inp[i], " -> ")
+		for j := range pts {
+			if start == nil {
+				start = h.CoordinateFromString(pts[j])
+			} else if end == nil {
+				end = h.CoordinateFromString(pts[j])
+			}
+			if start != nil && end != nil {
+				puts := GetLine(start, end)
+				for _, coord := range puts {
+					m.Put(*coord, '#')
+				}
+				start, end = end, nil
+			}
+		}
+	}
+	return &m
+}
+
+func GetLine(c1, c2 *h.Coordinate) []*h.Coordinate {
+	var ret []*h.Coordinate
+	if c1.X == c2.X {
+		if c1.Y < c2.Y {
+			for y := c1.Y; y <= c2.Y; y++ {
+				ret = append(ret, &h.Coordinate{X: c1.X, Y: y})
+			}
+			return ret
+		} else if c1.Y > c2.Y {
+			for y := c2.Y; y <= c1.Y; y++ {
+				ret = append(ret, &h.Coordinate{X: c1.X, Y: y})
+			}
+		}
+	} else if c1.Y == c2.Y {
+		if c1.X < c2.X {
+			for x := c1.X; x <= c2.X; x++ {
+				ret = append(ret, &h.Coordinate{X: x, Y: c1.Y})
+			}
+		} else if c1.X > c2.X {
+			for x := c2.X; x <= c1.X; x++ {
+				ret = append(ret, &h.Coordinate{X: x, Y: c1.Y})
+			}
+		}
+	}
+	return ret
+}