shithub: kwa

ref: 2af227c88bbcf8d6c52eb5b3b3a677d88a281774
dir: /test/t.randk/

{
	k = 2
	n = NF
	i = 1
	while ( i <= n ) {
		if ( rand() < k/n ) {
			print i
			k--
		}
		n--
		i++
	}
}