package q200

const (
	VISITED byte = '.'
	LAND    byte = '1'
)

func traverse(grid [][]byte, x, y int) int {
	if x < 0 || y < 0 || x >= len(grid[0]) || y >= len(grid) || grid[y][x] != LAND {
		return 0
	}

	grid[y][x] = VISITED
	traverse(grid, x+1, y)
	traverse(grid, x-1, y)
	traverse(grid, x, y+1)
	traverse(grid, x, y-1)
	return 1
}

func numIslands(grid [][]byte) int {
	count := 0
	for y := range grid {
		for x := range grid[y] {
			count += traverse(grid, x, y)
		}
	}
	return count
}

var _ = numIslands