shithub: trueawk

ref: 7d562f0dff4db4ea7f7e91f462c4adf552b1b410
dir: /testdir/t.randk/

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