func median_func(data lessSwap, a, b, c int, swaps *int) int {
	a, b = order2_func(data, a, b, swaps)
	b, c = order2_func(data, b, c, swaps)
	a, b = order2_func(data, a, b, swaps)
	return b
}

// medianAdjacent_func finds the median of data[a - 1], data[a], data[a + 1] and stores the index into a.
func medianAdjacent_func(data lessSwap, a int, swaps *int) int {