kleinberg, jon. algorithm design (p.426 q.20). your friends are involved in a large-scale atmospheric science experiment. they need to get good measurements on a set s of n different conditions in the atmosphere (such as the ozone level at various places), and they have a set of m balloons that they plan to send up to make these measurements. each balloon can make at most two measurements. unfortunately, not all balloons are capable of measuring all conditions, so for each balloon i