advent2022

commit 7732ec3c80ee414dad6b88aa7e8a14bb64b4b106
parent f23ede1b9a424b85bf48bccb95ed15399a2cb27a
Author: bsandro <email@bsandro.tech>
Date:   Wed, 14 Dec 2022 11:57:09 +0000

Day 14 part 2

Diffstat:
M
day14/main.go
 | 
90
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------

1 file changed, 70 insertions(+), 20 deletions(-)
diff --git a/day14/main.go b/day14/main.go
@@ -16,30 +16,27 @@ type Pos struct {
 type Shape []Pos
 type Shapes []Shape
 
-func (ss Shapes) GetMinX() int {
-	x := -1
+func (ss Shapes) GetLeftmost() Pos {
+	p := Pos{x: -1}
 	for _, s := range ss {
 		for _, e := range s {
-			if x == -1 {
-				x = e.x
-			}
-			if e.x < x {
-				x = e.x
+			if p.x == -1 || e.x < p.x {
+				p = e
 			}
 		}
 	}
-	return x
+	return p
 }
-func (ss Shapes) GetMaxX() int {
-	x := 0
+func (ss Shapes) GetRightmost() Pos {
+	var p Pos
 	for _, s := range ss {
 		for _, e := range s {
-			if e.x > x {
-				x = e.x
+			if e.x > p.x {
+				p = e
 			}
 		}
 	}
-	return x
+	return p
 }
 func (ss Shapes) GetMaxY() int {
 	y := 0
@@ -61,7 +58,7 @@ func (grid Grid) String() string {
 		for x := 0; x < len(grid[y]); x++ {
 			switch grid[y][x] {
 			case 0:
-				s += "."
+				s += " "
 			case 1:
 				s += "#"
 			case 2:
@@ -147,14 +144,14 @@ func day14(input_file string) {
 	}
 
 	height := shapes.GetMaxY() + 1
-	offsetX := shapes.GetMinX()
-	width := shapes.GetMaxX() - offsetX + 2
+	offsetX := shapes.GetLeftmost().x
+	width := shapes.GetRightmost().x - offsetX + 2
 	var grid Grid
 	grid.Init(width, height)
 	for _, s := range shapes {
 		grid.AddShape(s, offsetX)
 	}
-	fmt.Printf("%v\n", grid)
+	//fmt.Printf("%v\n", grid)
 
 	i := 0
 	for {
@@ -169,7 +166,6 @@ func day14(input_file string) {
 				p.y += 1
 				p.x += 1
 			} else {
-				//log.Fatal("invalid point")
 				break
 			}
 		}
@@ -181,6 +177,60 @@ func day14(input_file string) {
 		i++
 		//fmt.Printf("%v\n", grid)
 	}
-	fmt.Printf("%v\n", grid)
-	fmt.Println("grains of sand:", i)
+	//fmt.Printf("%v\n", grid)
+	fmt.Println("grains of sand 1:", i)
+
+	var grid2 Grid
+	height += 2
+	leftmost := shapes.GetLeftmost()
+	rightmost := shapes.GetRightmost()
+	minx := leftmost.x - (height - leftmost.y)
+	maxx := rightmost.x + (height - rightmost.y)
+	if minx > 500-height {
+		minx = 500 - height
+	}
+	if maxx < 500+height {
+		maxx = 500 + height
+	}
+	offsetX = minx
+	width = maxx - minx + 2
+	///fmt.Printf("minx:%d, maxx:%d,offsetx:%d,width:%d,height:%d\n",minx,maxx,offsetX,width,height)
+	if offsetX < 0 {
+		offsetX = 0
+	}
+	grid2.Init(width, height)
+	for _, s := range shapes {
+		grid2.AddShape(s, offsetX)
+	}
+	floor := Shape{}
+	floor = append(floor, Pos{x: 0, y: height - 1})
+	floor = append(floor, Pos{x: width - 1, y: height - 1})
+	grid2.AddShape(floor, 0)
+	//fmt.Printf("%v\n", grid2)
+	i = 0
+	for {
+		p := Pos{x: 500 - offsetX, y: 0}
+		for p.x > 0 && p.x < width-1 && p.y < height-1 {
+			if grid2[p.y+1][p.x] == 0 {
+				p.y += 1
+			} else if grid2[p.y+1][p.x-1] == 0 {
+				p.y += 1
+				p.x -= 1
+			} else if grid2[p.y+1][p.x+1] == 0 {
+				p.y += 1
+				p.x += 1
+			} else {
+				break
+			}
+		}
+		if p.y < height-1 && grid2[p.y][p.x] == 0 {
+			grid2[p.y][p.x] = 2
+		} else {
+			break
+		}
+		i++
+		//fmt.Printf("%v\n", grid2)
+	}
+	//fmt.Printf("%v\n", grid2)
+	fmt.Println("grains of sand 2:", i)
 }