Path Solving

mazer/maze.go

@@ -89,6 +89,99 @@ func GenerateMaze(width int, height int) [][]int {
 	return matrix
 }
 
+func FindSolutionPath(matrix [][]int) [][]bool {
+	height := len(matrix)
+	if height == 0 {
+		return nil
+	}
+	width := len(matrix[0])
+	if width == 0 {
+		return nil
+	}
+
+	startX := -1
+	endX := -1
+	for x := 0; x < width; x++ {
+		if matrix[0][x] == 1 {
+			startX = x
+			break
+		}
+	}
+	for x := 0; x < width; x++ {
+		if matrix[height-1][x] == 1 {
+			endX = x
+			break
+		}
+	}
+	if startX == -1 || endX == -1 {
+		return nil
+	}
+
+	start := startX
+	end := (height-1)*width + endX
+	parent := make([]int, width*height)
+	for i := range parent {
+		parent[i] = -1
+	}
+	visited := make([]bool, width*height)
+	queue := make([]int, 1, width*height)
+	queue[0] = start
+	visited[start] = true
+
+	dx := [4]int{0, 1, 0, -1}
+	dy := [4]int{-1, 0, 1, 0}
+
+	found := false
+	for head := 0; head < len(queue); head++ {
+		idx := queue[head]
+		if idx == end {
+			found = true
+			break
+		}
+
+		x := idx % width
+		y := idx / width
+		for i := 0; i < 4; i++ {
+			nx := x + dx[i]
+			ny := y + dy[i]
+			if nx < 0 || nx >= width || ny < 0 || ny >= height {
+				continue
+			}
+			if matrix[ny][nx] == 0 {
+				continue
+			}
+
+			nIdx := ny*width + nx
+			if visited[nIdx] {
+				continue
+			}
+			visited[nIdx] = true
+			parent[nIdx] = idx
+			queue = append(queue, nIdx)
+		}
+	}
+
+	if !found {
+		return nil
+	}
+
+	pathCells := make([]bool, width*height)
+	for idx := end; idx != -1; idx = parent[idx] {
+		pathCells[idx] = true
+		if idx == start {
+			break
+		}
+	}
+
+	path := make([][]bool, height)
+	for y := 0; y < height; y++ {
+		rowStart := y * width
+		path[y] = pathCells[rowStart : rowStart+width]
+	}
+
+	return path
+}
+
 func shuffledDirections() [4]uint8 {
 	dirs := [4]uint8{0, 1, 2, 3}
 	for i := 3; i > 0; i-- {