package q48

func rotateCell(matrix [][]int, x, y int) {
	t := matrix[y][x]
	for range 4 {
		nextX, nextY := len(matrix)-1-y, x
		matrix[nextY][nextX], t = t, matrix[nextY][nextX]
		x, y = nextX, nextY
	}
}

func rotate(matrix [][]int) {
	w := len(matrix)
	for y := range w / 2 {
		for x := y; x < w-y-1; x++ {
			rotateCell(matrix, x, y)
		}
	}
}

var _ = rotate