Moving right along

2019/day15/main.go

@@ -104,11 +104,44 @@ func play(prog []int) {
 			}
 		}
 	}()
-	ret := p.Run()
-	if ret == intcode.RET_DONE {
-		maze.Print()
-	} else if ret == intcode.RET_ERR {
-		fmt.Println("ERROR")
-		fmt.Println(p.Error())
+	p.Run()
+	//We force quit the program when the maze is built.
+	// Now we find the quickest path through the maze.
+	fmt.Println(helpers.CLEAR_SCREEN)
+	maze.Print()
+	fmt.Println("Now find shortest path")
+	done, ret := BFS(maze.bfs[maze.startCoord], maze.bfs[maze.o2Coord])
+	if done {
+		fmt.Println("Found Route")
+	} else {
+		fmt.Println("No Route Found")
 	}
+	fmt.Println("Steps:", len(ret))
+}
+
+func BFS(start, goal *BFSNode) (bool, []*BFSNode) {
+	var queue, explored []*BFSNode
+	queue = append(queue, start)
+	if start == goal {
+		return true, queue
+	}
+	explored = append(explored, start)
+	for len(queue) > 0 {
+		var current *BFSNode
+		if len(queue) > 1 {
+			current, queue = queue[0], queue[1:]
+			if current == goal {
+				return true, explored
+			} else {
+				children := current.getChildren()
+				if len(children) != 0 {
+					queue = append(queue, children...)
+				} else {
+					return false, explored
+				}
+			}
+		}
+		explored = append(explored, current)
+	}
+	return false, explored
 }

2019/day15/maze.go

@@ -28,22 +28,55 @@ type Maze struct {
 	path       []*helpers.Coordinate
 	dirHistory []int
 	dnt        bool
+
+	bfs map[*helpers.Coordinate]*BFSNode
+
+	startCoord *helpers.Coordinate
+	o2Coord    *helpers.Coordinate
 }
 
 func NewMaze() *Maze {
 	m := &Maze{
-		maze: make(map[string]int),
-		maxX: helpers.MIN_INT,
-		minX: helpers.MAX_INT,
-		maxY: helpers.MIN_INT,
-		minY: helpers.MAX_INT,
-		bot:  helpers.NewCoordinate(0, 0),
+		maze:       make(map[string]int),
+		maxX:       helpers.MIN_INT,
+		minX:       helpers.MAX_INT,
+		maxY:       helpers.MIN_INT,
+		minY:       helpers.MAX_INT,
+		bot:        helpers.NewCoordinate(0, 0),
+		bfs:        make(map[*helpers.Coordinate]*BFSNode),
+		startCoord: helpers.NewCoordinate(0, 0),
 	}
 	m.path = append(m.path, helpers.NewCoordinate(0, 0))
 	return m
 }
 
 func (m *Maze) SetCoord(c *helpers.Coordinate, val int) {
+	var b *BFSNode
+	var ok bool
+	if b, ok = m.bfs[c]; !ok {
+		b = &BFSNode{Value: val}
+		m.bfs[c] = b
+	}
+	// Create the BFS node for this
+	if n, ok := m.bfs[c.GetNorthCoord()]; ok {
+		n.South = b
+		b.North = n
+	}
+	if e, ok := m.bfs[c.GetEastCoord()]; ok {
+		e.West = b
+		b.East = e
+	}
+	if s, ok := m.bfs[c.GetSouthCoord()]; ok {
+		s.North = b
+		b.South = s
+	}
+	if w, ok := m.bfs[c.GetWestCoord()]; ok {
+		w.East = b
+		b.West = w
+	}
+	if val == 2 {
+		m.o2Coord = c
+	}
 	m.maze[c.String()] = val
 	if m.maxX < c.X {
 		m.maxX = c.X
@@ -137,3 +170,26 @@ func (m *Maze) Print() {
 		fmt.Println()
 	}
 }
+
+type BFSNode struct {
+	Value       int
+	North, East *BFSNode
+	South, West *BFSNode
+}
+
+func (b *BFSNode) getChildren() []*BFSNode {
+	var ret []*BFSNode
+	if b.North != nil {
+		ret = append(ret, b.North)
+	}
+	if b.East != nil {
+		ret = append(ret, b.East)
+	}
+	if b.South != nil {
+		ret = append(ret, b.South)
+	}
+	if b.West != nil {
+		ret = append(ret, b.West)
+	}
+	return ret
+}